I think the forum is generally very courteous, especially to beginners. I've seen some shots that have been very poor, technically and artistically, we all know the ones I mean, and not only has nobody commented on it, they've received likes, because the person is obviously a beginner, and encouragement is what's needed. Conversely I've seen shots that personally I really liked that have been ripped to shreds, just because what they wanted to achieve is different to what you wanted the shot to do, that's artistic difference, you'll never agree on that.
Tee ones that crack me up are the journalistic ones where people criticise something in the background, what's the photographer meant to do, ask the 70 strangers in shot to reply the last 30s of their lives, knock the ugly building down, ask the train to back up and have another go....