In my opinion, there's a difference between quality post and merited posts. If you ask for what quality posys are, I can't give a definite answer since the forum didn't define what quality posts are. But when you talk about merited posts, they are posts that are contributing positively to the discussion at hand.

These posts must not be agreeing to the topic been discussed, it could be a contradicting view but does has meaning and quality to it. While the level of your post quality depends on the users with the smerit that doesn't mean any posts that don't get merited isn't quality.

Some just lack the exposure needed for meriters to see. Providing you're contributing positively to a discussion ongoing and aren't spamming or posting generic contents you're good to go as your post could be considered quality by a merit source and get rewarded.