Army secretary open to renaming military bases named for Confederate generals
https://muse.jhu.edu/article/722208
Project MUSE - Braxton Bragg: The Most Hated Man of the Confederacy by Earl J. Hess...
If there is one thing most military historians of the Civil War can agree upon, it is this: Gen. Braxton Bragg failed as the main Confederate commander in the western theater. Historians may differ as to which trait ultimately sunk Bragg's leadership, whether it be poor operational and strategic command, thin-skinned sensitivity to criticism, overaggressive use of force against deserters, or under-aggressive use of force against the Federal...
So yes, they were protecting their homes, but the reason they needed to do that was because by and large they signed on to attempt a rebellion to preserve slavery. If we claim, "well it was complicated", for those German soldiers, the same is true of the Confederate rank and file.
"I highly doubt that there are too many Confederate diary entries out there where men are stating how they are going to fight for the institution of slavery."
This is actually a very incorrect and you are also wrong that they were largely uneducated. The interesting thing about the Civil War is that it was the first war with a highly literate rank and file on both sides. What makes this interesting is in that period the soldiers wrote and they wrote a lot. Much of this still survives so we don't really have to guess as to their motivations here either.
Even the idea that they were just fighting for their homes is extremely simplistic, they were by and large very politically opinionated. A good book to read is, "For Cause and Comrades: Why Men Fought in the Civil War" written by James M. McPherson.
https://www.amazon.com/Cause-Comrades-Why-Fought-Civil-ebook-dp-B000SH5ZOG/dp/B000SH5ZOG/ref=mt_other?_encoding=UTF8&me=&qid=
Amazon.com: For Cause and Comrades: Why Men Fought in the Civil War eBook: McPherson, James M.:...
Amazon.com: For Cause and Comrades: Why Men Fought in the Civil War eBook: McPherson, James M.: Kindle Store
Even on the Northern side things were more complicated. For a long time I had always thought that most of the soldiers on the north were not about abolishing slavery but about preserving the Union. As it turns out a surprising number of them actually did hold very strong anti-slavery abolitionist views and that motivated their service.