If it has to be per excellence, then some posts that have received merits here shouldn't or ought not to, it's a thing if the giver's discretion based on what the reader must have drown out of the post which might not be same to other's perspective. I have come seen some thread of good punctuation and presentation but yet no quality in the message in claim to posses. Like someone said, merit is just an incentive for a job well done and not per excellence.
Don't forget that giving merits is sometimes quite subjective. Although you think it is a good post and deserves merits, other people may think it is just an ordinary post. A good post isn't only determined by punctuation and presentation, the most important is its content. It is useless if a post has no point, good punctuation and presentation are just complements.