But they were not idiots and so did not subscribe to your facile rationalization.
Had Congress engaged in the extraordinary occupation of improving the Constitutions of the several States by affording the people additional protection from the exercise of power by their own governments in matters which concerned themselves alone, they would have declared this purpose in plain and intelligible language.But it is universally understood, it is a part of the history of the day, that the great revolution which established the Constitution of the United States was not effected without immense opposition. Serious fears were extensively entertained that those powers which the patriot statesmen who then watched over the interests of our country deemed essential to union, and to the attainment of those invaluable objects for which union was sought, might be exercised in a manner dangerous to liberty. In almost every convention by which the Constitution was adopted, amendments to guard against the abuse of power were recommended. These amendments demanded security against the apprehended encroachments of the General Government -- not against those of the local governments.
But it is universally understood, it is a part of the history of the day...
By citing John Marshall's decision in Barron v Baltimore, I guess you have provided your answer that you agree with the Kelo decision that empowers the states to seize private property for any reason they deem to be justifiable under the takings clause. In fact, I suppose you would argue that the takings clause doesn't even apply at all since that is only a restriction on the federal government. Of course the case you are citing has been pretty much overturned by the SCOTUS -- sort of like Dred Scott has.