[@Dervish] the key for me is who is giving it and how they are giving it.

If Jan Doodlebag is telling me that my posts suck and that I need to do this and this better, when his posts look like someone vomited on a keyboard and the chunks of food in there happened to hit some keys, and then he hit send, I'm going to tell him in the nicest of ways how he should find a nearby metal rod and stick it up his ass.

If a veteran that has objectively superior posts tells me that I should pay attention to these things, but these things are good, and this could improve, then yeah, sure, I'd appreciate that.

I [i]do[/i] have problems with people in my RP's that I GM that do this, because it's annoying as fuck. If I already cleared a character sheet and gave them a review, I don't need a non-GM to go in and tell them, while pushing their fucking glasses back onto their face, 'ackshually...' all smug-like and tell them everything that is wrong with a character. I also don't need people to go out of their way to tell people their posts suck, or something. Because I as a GM am very fucking active and I don't shy away from criticism, especially early on in the CS stage. 

Now the problem for that doesn't come from the fact that people are giving feedback because I'd appreciate that, as a bystander, someone is taking time out of their day to comment and critique someone in a constructive way. 

The problem is that most people on RPG happen to be extremely smug and, like mentioned before, suffer from Dunning-Krugers. And I'm gonna take the hard stance on that and just say fucking everyone here suffers from it, because the people who actually know how to offer advise are typically too fucking nice to do so on this website.

It has so far in my experience been [i]impossible[/i] for someone to give feedback while not in a GM position. Either they try too hard to be 'objective' and come across entirely as some dumbass that wants to shit on someone and portray their opinion as facts, or they just base their entire feedback on their own opinions. 

I guess what I'm trying to say is that in theory feedback and criticism is nice, totally dope and the best thing ever but that, as with 99% of other issues on RPG, the people on RPG are just too stupid (in my experience, so far) to be able to do it in a way that isn't condescending or downright insulting.