Editing a large number of questions, e.g. to fix a tag, is very annoying. If you do it all at once you push everything else from the frontpage and make it useless, and making the new questions that need the attention less visible. If you space it out, you have to remember to regularly do a handful of edits at a time. That is very discouraging if there are lots of questions still to fix, and it is easy to lose track, meaning you'll revisit the same questions again that you already examined earlier. Keeping tags unambiguous and useful is important, but it requires a lot of work and it is made much more difficult and annoying than it has to be by the current system.
Not all users know about the drawbacks of mass retags. They're trying to help and fix stuff but accidentally break the frontpage as well. Then you have to tell them that they're doing it wrong; well actually they're doing the right thing but just a bit too fast and they should slow down.
Then you'll get some discussions as nobody can agree on how much frontpage breakage is acceptable. And in the end many users probably decide to just not bother with fixing such large scale tagging problems due to all the annoyance this causes.
Another problem is that at the point where a moderator sees that a user is editing too fast, the frontpage is usually at least half-broken already. So the damage is often done, and it can't be undone.
Ideally, users wouldn't even be able to push everything else from the frontpage by editing old stuff. They also shouldn't have to care about how fast they edit or retag. They should only have to care about the quality of their edits.
To achieve this, I propose that edits to older posts are queued and not immediately applied if the editing user already has more than x posts on the frontpage (due to bumping). The edits would be like suggested edits, but not appear in the suggested edit queue. The system would then automatically space out the edits and slowly apply them without breaking the frontpage. This would not apply to very recent questions (that are still on the frontpage), and any user accessing the question directly should still be able to approve or improve the pending edit.
Moderators would get a "nuke all queued edits from this user" ability to solve cases where a user did some stupid mass edits that shouldn't happen at all.
This feature would solve two problems, it would prevent anyone from breaking the frontpage with mass edits, accidentally or not, and it would make it far more convenient to perform mass edits in our own time.