Yes I do (well, I rebase, not squash blindly), but I do read the commit history. Or well, not so much the complete history, but I do go looking for which commit introduced a particular line, what message went with that change, and what else changed with it.

Of course, that only works after you leave proper commits. The reason people don't do that is because you only look at your commit history if you've kept it useful, but if you've never looked at your commit history because it's not, you don't know the benefits of keeping it useful.