Well according to you, you say it was the engine of their economy. What would you feel like if someone decided to say, stop you from using fossil fuels because they thought it was a great moral imperative for you to do so?
Say they had this great moral crises, like, oh, I don't know, "Global Warming" and the only solution is that you have to stop using fossil fuels, but not them of course.
I dunno, if someone wanted to gut the engine of my economic activity, I would be concerned about it. On the other hand, you can let me know when you stop driving cars or heating your home. Electricity? Well that's out too, unless you live up in Hydroelectric Oregon or New York.
A reasonable point.
Except that abolitionists weren’t using slaves, so they weren’t trying to make southerners stop using them while continuing to use them themselves.
The problem was not that slavery would be easy to get rid of. Every reasonable person agreed it would not be easy. Lincoln stated many times that it would be very difficult.
However, the Republican position was simply that a great evil doesn’t become good because it’s difficult to get rid of. First agree that it is an evil, and then we can discuss ways of reducing and eventually eliminating it.
But southerners, increasingly over the 19th century and very nearly unanimously by 1860, refused to agree slavery was an evil. They insisted it was a positive good and should be continued forever and spread into new areas.
That’s what Republicans objected to and to support which the original seven states seceded.