GM's in RPs

So, I was on another site browsing around when an interesting topic regarding GM's came up. There was a roleplay which of course had a GM. Said GM made comments in the OOC towards some users not others about their character sheets, acknowledging them but made no comments on others. Now, the GM wasn't accepting character sheets first come, first served. They were going to choose the ones that best fit for what they were looking for in the RP.

One player apparently seemed pissed at this and dropped out of the RP saying that it was favoritism because it appeared the GM was friends with the users they were acknowledging, but was rather harsh in how he stated it all - I don't want to quote anything here just in case people from there are here. The IC hadn't started at this point still.

What do you think of this kind of situation?

Is it fair that a GM comments on some things and not on others?

My opinion is that it doesn't matter. While it is nice to have your hard work noticed straight away in the OOC, I don't need to have a direct comment made unless something is wrong about the character and needs correcting. I'd be happy to wait until I found out if I was accepted or not.

If I had a big problem I wouldn't go and post it to the OOC either, I'd go and send them a PM instead. As a previous GM I know I've commented as soon as a friend has joined my RP and possibly not commented on other players, though I try to at least give a comment to everyone's posts when needed.

So, what's your opinion on this type of situation?