I've been happily making minor edits to questions and titles for months, but it was only today I noticed that there's a concept of "you haven't edited this enough for your edit to be accepted", with this message:
This edit is too minor; suggested edits should be substantive improvements addressing multiple issues in the post.
(The message wasn't directed at me.) At first glance this is odd - it's going to encourage editors to make additional and possibly unnecessary changes just to get over some threshold, just like people typing extra characters into a comment to get over the minimum count. People will start changing British or Australian English to American English, or looking for any nitpick they can, just to bump up the numbers.
I've browsed some Meta StackOverflow questions (e.g. this one) but I saw no compelling reasons to justify this. There's seems to be no technical reason. It might make additional work for reviewers if there are more smaller edits, but on the other hand it's easier to approve batches of minor edits than to wade through questions that have been comprehensively shredded and re-assembled.
Also, in this particular case, it meant that I was unable to fix a typo in the title for about 3 hours (the question was edit-locked or something). The editor in question had simply italicized Mathematica and removed an unnecessary "thank you" at the end; minor edits to be sure, but why should more edits be made just to get those ones through?
Given the generally poor state of so many questions these days, with questioners even starting to develop their own custom formatting rules or just not bothering to read the FAQ before asking, why is there this restriction that edits must, like London buses, only travel in groups? Or is this being applied only to users with certain reputation levels? If so, isn't there the risk that this policy will discourage people from contributing more to the site?