That's good, because I find I often fix multiple related bugs with a large commit. https://gerrit.wikimedia.org/r/#/c/187840/ would take care of three, if the other two ("change password" and "change email") were to be filed. Maybe 4 if you count working on the "refactor 'business logic' out of special pages" technical debt bug we might have floating around somewhere.

And in the other direction there would be stuff like https://gerrit.wikimedia.org/r/#/q/branch:master+topic:api-cleanup-results,n,z, 37 "update $extension for core change" tasks and then customizing the commit summaries for each would probably be a big waste of time.

I don't think filing phab tasks for "I have to clean this up because my eyes are bleeding" would necessarily be better than a good commit summary as far as indicating what goal the patch is supposed to be solving. As in "when I've felt the need to do this in the past, I often used basically the same text for the task and the commit summary". On the other hand, I tend to be more verbose in my commit summaries.

And in some cases (e.g. https://gerrit.wikimedia.org/r/#/c/187150/), filing a task could take longer than it did to make the commit in the first place.