Perhaps it is because the 'cold hard facts' all indicate that the defense of the institution of slavery was the primary reason for secession? If one reads the Declaration of the Causes of Secession for the various states it becomes clear. Mississippi, for example, said,
"In the momentous step which our State has taken of dissolving its connection with the government of which we so long formed a part, it is but just that we should declare the prominent reasons which have induced our course.
Our position is thoroughly identified with the institution of slavery-- the greatest material interest of the world. Its labor supplies the product which constitutes by far the largest and most important portions of commerce of the earth. "
Georgia said,
"The people of Georgia having dissolved their political connection with the Government of the United States of America, present to their confederates and the world the causes which have led to the separation. For the last ten years we have had numerous and serious causes of complaint against our non-slave-holding confederate States with reference to the subject of African slavery. "
Texas said,
"Texas abandoned her separate national existence and consented to become one of the Confederated Union to promote her welfare, insure domestic tranquility and secure more substantially the blessings of peace and liberty to her people. She was received into the confederacy with her own constitution, under the guarantee of the federal constitution and the compact of annexation, that she should enjoy these blessings. She was received as a commonwealth holding, maintaining and protecting the institution known as negro slavery-- the servitude of the African to the white race within her limits-- a relation that had existed from the first settlement of her wilderness by the white race, and which her people intended should exist in all future time. "
Alexander Stephens, vice president of the confederacy, said,
"But not to be tedious in enumerating the numerous changes for the better, allow me to allude to one other -- though last, not least. The new constitution has put at rest, forever, all the agitating questions relating to our peculiar institution -- African slavery as it exists amongst us -- the proper status of the negro in our form of civilization. This was the immediate cause of the late rupture and present revolution."
The southern leadership - in it's own words - makes it clear what the most important factor in their decision to enter into rebellion was and that was the institution of slavery.
You keep quoting these so-called 'declarations of the causes' like you want to fool someone (or have been fooled) into believing that these mostly unattributed wastebasket tossings skimmed from a virtual warehouse of contrasting evidence are some kind of official documents.
You do yourself and the good posters here a great disservice when you define the people of the time inaccurately. Here are their words:
South Carolina Declaration of Causes of Secession (December, 1860):
“We assert that fourteen of the States have deliberately refused, for years past, to fulfill their constitutional obligations, and we refer to their own Statutes for the proof.”
“The guaranties of the Constitution no longer exist; the equal rights of the States are lost.
(Southern) States will no longer have the power of self-government, or self-protection, and the Federal government will have become the enemy.”
Georgia Secession Decree (January, 1861):
“(The Northern States) have endeavored to weaken our security, to disturb our domestic peace and tranquility, and refused to comply with their constitutional obligations to us in reference to our property, and by the use of their power in the Federal Government have striven to deprive us of an equal enjoyment of the common Territories of the Republic.
“The people of Georgia, after a full and fair and deliberate hearing of the case, have declared with firmness that (the Northern States) shall not rule over them.”
Mississippi Secession Decree (January, 1861): “(The North) has given indubitable evidence of its design to ruin our agriculture, to prostrate our industrial pursuits and to destroy our social system.
“Utter subjugation awaits us in the Union, if we should consent longer to remain in it. It is not a matter of choice, but of necessity (to secede).”
Texas Secession Document (February, 1861)
“The controlling majority of the Federal Government, under various pretences and disguises, has so administered the same as to exclude the citizens of the Southern States, unless under odious and unconstitutional restrictions, from all the immense territory owned in common by all the States on the Pacific Ocean, for the avowed purpose of acquiring sufficient power in the common government to use it as a means of destroying the institutions of Texas and her sister slaveholding States.”
South Carolina’s address to other Southern States (December, 1860)
“The Southern States now stand in a minority in Congress. Their representation in Congress is useless to protect them against unjust taxation, and they are taxed by the people of the North for their benefit.
For the last forty years the taxes laid by the Congress of the United States have been laid with a view of subserving the interests of the North.
“The people of the South have been taxed by duties on imports not for revenue, but for an object inconsistent with revenue -- to promote, by prohibitions, Northern interests in the productions of their mines and manufactures.”
Louisiana Secession Document (January, 1861):
“The people of Louisiana are unwilling to endanger their liberties and property by submission to the despotism of a single tyrant, or the canting tyranny of pharisaical majorities(in the North).
Mississippi Secession Document (January, 1861):
That they have elected a majority of electors for President and Vice-President on the ground that there exists an irreconcilable conflict between the two sections of the Confederacy in reference to their respective systems of labor and in pursuance of their hostility to us and our institutions, thus declaring to the civilized world that the powers of this government are to be used for the dishonor and overthrow of the Southern section of this great Confederacy.
South Carolina Declaration of Causes of Secession:
We affirm that these ends for which this government was instituted have been defeated, and the government itself has been destructive of them by the action of the(North).”
Virginia Secession Document (April, 1861):
The people of Virginia, in their ratification of the constitution of the United States of America, having declared that the powers granted under the said constitution were derived from the people of the United States, and might be resumed whensoever the same should be perverted to their injury and oppression; and the federal government having perverted said powers, not only to the injury of the people of Virginia, but to the oppression of the southern States”. Alexander Stephens, Cornerstone Speech, (March, 1861):
Allow me briefly to allude to some of these improvements (of the new Confederate Constitution over the old Union Constitution). The question of building up class interests, or fostering one branch of industry to the prejudice of another under the exercise of the revenue power, which gave us so much trouble under the old constitution, is put at rest forever under the new.
“We allow the imposition of no duty with a view of giving advantage to one class of persons, in any trade or business, over those of another.
“This old thorn of the tariff, which was the cause of so much irritation in the old body politic,is removed forever from the new.
Jefferson Davis’ Farewell Address to the Senate (January, 1861):
“It has been a belief that we are to be deprived in the Union of the rights our fathers bequeathed to us, which has brought Mississippi into her present decision.”
“A State, finding herself in the condition in which Mississippi has judged she is, in which her safety requires that she should provide for the (secession) out of the Union…”