Is this supposed to be another one of your "reductio ad absurdums" that looks suspiciously like just another strawman misstatement of my position?
Yes, Slavery was/is a bad thing. It should never have been allowed to take root here in the first place. It is a product of the Muslim Religion, and inconsistent with the Christian one, but some people are too willing to tolerate slavery if it makes a buck for them. (Washington D.C. is currently full of them.)
That being said, your point deliberately ignores the reality of the situation in 1861. Slavery was both legal and represented a very significant portion of the the South's financial assets and Gross Domestic product.
How about you tell me how much that "peculiar institution" was worth to them? Then you can tell me if that cost would represent a "light and transient" cause.
Okay, and what threat did Lincoln's election pose to slavery, given that he repeatedly stated that he had no intention of interfering with it except to prevent its extension into the territories and his belief that complete abolition would require a constitutional amendment, something very unlikely to happen in the face of southern opposition?