Presumably the impetus is that if you fix a bunch of small things in a single commit it might be easier to compile the list of small things you changed by noting them as comments as you fix them rather than trying to remember them after the fact when it comes time to write a commit log for that commit.

That said, philosophically I'd personally prefer to just commit the small features individually as a set of small commits, therefore you get a better git blame/praise experience with the end result, but I realize there is a wide spectrum of preferences on commit size and style.