Thank you for your reply. Yes, I agree with @nuoctuong and you on the part that quality is subjective.
It would be best to restrict users who make a lot of grammatical mistakes. If something is on the front page, it should be well-written and should have little to no grammatical mistakes. A few mistakes can be overlooked but not many.
But it would be best if you combine this one with other ways you'll implement to make sure we don't lose great content just because of grammatical mistakes.
Thanks for the suggestion, we'll add this in our list.