I think a great deal of this comes from inexperienced reviewers trying to get through their day's allocation of reviews as quickly as possible to bring in the rep points.
I don't understand it, therefore it's "unclear".
If the question needs only that you do understand the topic, then I flag these as 'no longer needed', which then means a mod has to go to the bother of removing it.
In the meantime, I'm trying to get at least a first draft of an answer in, before it gets hammered into submission.
More experienced users will tend to vtc inside the question itself, rather than from review. If it really is a garbled mess, fine & dandy, try to get the user to make some sense - no point doing all the work for them, if they can't be bothered.
If, however, it's nothing more than a bit of newbie formatting that can be quickly rescued… rescue it.
No-one was born already knowing that markdown needs two spaces before a return & two returns to make a paragraph. It's easy to see if they tried single new-lines, saw they didn't really work in the preview… but then didn't know what else to try. Maybe they thought it would 'fix' itself once posted - some online forums do this, the preview is an even less accurate version of the final post than ours is.
For those, then, that are suffering only from 'rep point rushing' we need education.
I see a lot of these that have a single review comment. I check the review history & can see who did it - but there's no way to contact them to try educate. You can't reply to the bot, of course.
Perhaps this is an issue with how the review queues open up at certain privilege levels. I'm not sure it can be 'fixed' because it's invariably newer users fresh to the queues who are doing this. Raise the amount of reputation required might be one idea - but it may just push the issue further up the chain, and also mean fewer users are actually reviewing. Double-edged sword.
So - how do we educate?
The only way I can see it happening at present would be if a mod messages them with some words of advice. More work for the mods. No-one is gonna want that.
Perhaps we could sit a banner above the review queues, or pop a notice if they want to add that particular review comment…?
Are you certain this is actually unclear, or do you just not understand the topic?
Don't review topics you don't understand.
Use the Skip button instead.