I didn't say they were right. I am merely pointing out it is historically inaccurate to assume that people held the same view on secession that we hold today. Jefferson wrote at length on the subject and it was discussed many times in many different contexts between the founding and the Civil War. It would be wrong to suggest that everyone who formed the original confederation was under the impression it could not be dissolved, or individual states could not opt out. Here is an interesting article on the subject from Walter Williams.
http://capitalismmagazine.com/2002/04/do-states-have-a-right-of-secession/
With all due respect to Walter Williams who's commentaries I enjoy, he's cherry-picking to make his point. Thomas Jefferson, who was not a delegate said what he believed as a Virginian and he certainly wasn't by himself. Williams quotes James Madison which is a surprise given Madison's absolute opposition to secession outside of the means established within the Constitution. Even some quoted by Williams as favoring secession were actually opposed to violence as a means of settling the question. He again cherry-picks the NY Tribune as Greeley was opposed to a war and wanted a peaceful settlement of the question, though later turned his paper into a proponent of Radical Republican ideas on war with the South. He seems to ignore the many voices speaking out against secession while concluding that the 9th and 10th Amendments meant the framers wanted the states to have the right of secession.
Even the handful of Federalists who proposed secession after Jefferson's election knew it wasn't going anywhere as it simply wasn't a popular notion.
But I do agree, in spite of the logic of moving from a perpetual confederation to a more perfect union, and providing the means to change the Constitution, everyone didn't agree. But then, there was nothing in that convention and subsequent ratification debates that everyone agreed to.
Even the majority opinion in Texas v White concluded there was a proper means of achieving a dissolution, and Texas did not meet that standard. But the debate continues, and like a few other constitutional issues will always have two sides.