In my opinion, a single trailing question mark in the title is never worth an edit. Following the guidelines given in the MSE FAQ on good question titles (How do I write a good title?) the title should have received a complete rewording instead of an additional, redundant question mark. (Readers should be assumed to "understand your titles are questions.") So, yes, this edit adds no improvement whatsoever (and I would likely have rejected and edited it myself).
As for the too minor edits debate in general, I think especially new editors should be pointed more effectively (or more often, depending on the number of trivial edits they suggest) to the edit privilege description pageedit privilege description page:
When should I edit posts?
Any time you feel you can make the post better, and are inclined to do so. Editing is encouraged!
Some common reasons to edit are:
- to fix grammatical or spelling mistakes
- to clarify the meaning of a post without changing it
- to correct minor mistakes or add addendums / updates as the post ages
- to add related resources or hyperlinks
Try to make the post substantively better when you edit, not just change a single character. Tiny, trivial edits are discouraged.
As a suggestion to raise both reviewer's and editor's awareness of the issue I have posted a suggestion that addresses the issue. It is intended to make reviewers think about their action by requiring them to tick a reason why the edit should be approved:
Feel free to criticize.
