The badges for editing posts explicitly exclude tag edits. I understand why - they are supposed to reward substantial edits.
At the same time, tags are useful, necessary, for how Stack Exchange works: they are needed so people can find relevant questions, and so people can be notified there's a question they might be able to answer. So, it follows that someone who spends time correcting tags on questions does a service to the community.
So could there perhaps be some separate badge for editing tags? "Edited tags on 250 questions - Silver, Edited tags on 1000 questions - Gold", or something like that?