And as has been pointed out to you ad infinitum, The answer to that question makes the reasons irrelevant. Given your answer, who cares about their reasons? They don't have the right to leave anyways!
They are effectively bound by chains, like a slave.
You say “They are effectively bound by chains, like a slave.”
You say that like it was a bad thing. The states that seceded obviously did not agree, as that was why they seceded.