It would be nice if we were told why a cover is rejected but that's not how it works.
I tried that for a while but stopped because listing all flaws is tedious and answers were mostly in style of: Fuck you, the quality is not that bad, quit nitpicking.

So I got bored.

I still sometimes answer someone directly sends me a link to cover and asks.

I'm honestly to the point where I'm not even going to bother anymore.
If you want feedback just link me one of the covers you believe is site worthy and I'll see.
I might even accept it if quality is high and I manage to fix my connection which fucked up after upgrading to Windows 10 (whole computer is acting up, even after clean install. Might have do it again).