I've always been uneasy about the fact that Stack Overflow users can edit each other's posts more or less arbitrarily. User A can edit user B's post to say something embarrassing, and most readers will attribute it to User B.
I've had this happen with my posts. It's never been egregious, like a user inserting something inflammatory into my otherwise mundane programming question. Most often, the offending edits give the appearance that the original poster doesn't know how to write or doesn't know basic programming concepts. It's not unheard-of for potential employers to look at a programmer's accounts on Stack Overflow, Github, etc., so an unflattering edit could be problematic.
Granted, one can use a pseudonymous account. But it would be better not to have to.
You should receive a notification whenever someone else edits one of your posts. If the edit is inappropriate, you can revert it or re-edit it. "Edit wars" do happens sometimes, but they're discouraged, and you can always flag for moderator attention if it comes to that.
I didn't realize how much edit comments (description of changes) mattered until I saw some of my deleted/unapproved edits. E.g. Editing an answer to add an environment variable that was actually required was denied. I ended up writing it as a comment and had someone thank me for it in the comments. Had the edit been accepted there would have been less comment spam and more "good answer" on that page...
Every edit "bumps" the post, giving it a bit more visibility.
Some folks, upon encountering an unanswered question they also want an answer to, will do some quick copy-editing just to try & get a few more eyeballs on the problem.
There's only a specific group of people that "benefit" from editing questions. Most edits are an attempt to make it even slightly better and/or clearer in some way.
I've had this happen with my posts. It's never been egregious, like a user inserting something inflammatory into my otherwise mundane programming question. Most often, the offending edits give the appearance that the original poster doesn't know how to write or doesn't know basic programming concepts. It's not unheard-of for potential employers to look at a programmer's accounts on Stack Overflow, Github, etc., so an unflattering edit could be problematic.
Granted, one can use a pseudonymous account. But it would be better not to have to.