Minor edits (especially thinking about tag edits here) update the timestamp on a question and therefore "bump" it up the list of "recent" questions. 99% of the time this is just noise and shows people old questions they would just as soon not see. Often one sees 20 straight question all "bumped" by the same tag edit. Is it really necessary to update the timestamp in such cases?
For the record, I'm not a question bumper or mass re-tagger. However, I have to say that I do like questions being bumped up the queue every so often.The reason for this is the queue is very long and includes many questions that are of a very common garden variety. Questions that get bumped up quite often stand a higher chance of being genuinely interesting than other questions, in my opinion. Even if the edits are only minor (quite often they're in response to comments), these tend to occur on more interesting and helpful questions. I agree that mass tagging shouldn't warrant bumping up, but otherwise I welcome seeing older questions cropping up every now and then.
The best way to prevent old questions from being bumped because of tag edits would be to fix their tags when they were first asked!
There has been some recent discussions about how to encourage people to edit more. This is another reason why we need more editing.
Every day dozens of poor questions get asked which could be edited. If you want to help, then just get going! :)