Nope. Jamming together related changes is bad also. Now, of course, someone who makes a new commit every time they make a minor change, like three commits to f

Nope. Jamming together related changes is bad also. Now, of course, someone who makes a new commit every time they make a minor change, like three commits to fix three spelling errors in a comment, should be squashing that. That's a strawman. Changes that serve a different logical purpose in a related change set should be separate.