It has nothing to do with post count, just the quality of the fits, criticism, and advice. There are some fantastic posters with lower post counts who obviously know what they are talking about and consistently post inspiring fits (eg. Platypus), as well as members with high post counts who consistently post poor fits and add very little in the way of constructive criticism. But lackluster fits and comments will be criticized, hopefully for the sake of inspiring improvement, regardless of post count. If someone posts a poor or experimental fit they should expect criticism, again, regardless of post count.
Listen up lurkers; no one fucking cares about your opinion. If you want people to, then post actual FITS so other people can decide whether or not your advice is worth taking. This isn't MFA where a bunch of anonymous wankers can post generic advice yet never post their pictures. Honestly, the internet is already filled with bad advice, there's no need to clutter SF with it.