Among aspiring writers, one of the hardy perennial arguments (or rows, or flame wars, depending on the forum) is about when and how much the members should be critical and challenging... or is that vicious? And when and how much they should be supportive and empathic... or that sycophantic? Which is more likely to improve your writing, and which is more likely to be enjoyable? And no, the answer to that last question isn't necessarily what you might think. It's genuinely a complicated question, I think, and yet a very important one, if you're going to find the right places for your writerly self to hang out, meet other writers in the same boat, and learn to be a better writer.
Leaving aside the forums where there's active bullying going on, let's assume that we're in a forum where everyone is basically well-intentioned, and wanting to help. And let's also leave aside the question of being supportive about external things - rejections, disappointments, blocks and panics and deep gloom. It's perfectly possible to be honest about how sorry you feel for a rejected writer, while knowing that the work was quite possible nowhere near good enough. The two things are, if you like, separate value systems, and both have their place in a forum: unconditional support is enormously important for those bad times, just as critical scrutiny is at others. But for now, let's stick to the question of feedback on writing-related stuff.
Firstly, some people are more thick-skinned than others: with some writers, it takes four-letter words to convey the fact that something they've written really won't do, while with other writers saying 'I wasn't altogether convinced that..." is more than enough to get them revising furiously.The daft thing is that these two different styles can be saying exactly the same thing: X doesn't work, but Y does. Some people giving feedback are blunt, either as a product of their own thick-skinnedness or as a matter of style or, less attractively, machismo. And others giving feedback are thin skinned or anti-confrontational, and will put things more gently. So the trouble arises when there's a mis-match between the two parties. For a writer used to a macho style, gentle feedback is too tactful, too elliptical, just not loud and clear enough for them to hear the feedback at all. For a writer who's sharp-eared enough to hear the slightest whisper of a comment, macho feedback be genuinely and unhelpfully painful: if the music's much too loud, the sharp-eared can't hear what it's saying.
Widening out from the single pair of writer-reader, a macho feeder-back, seeing other, gentler comments may judge them sycophantic or useless, when a sharp-eared writer might find them detailed and useful. While a gentle feeder-back may cringe, on behalf of the writer, at some macho comments, without realising that a macho writer needs comments to be made with that much force.
But it's also about what you want, as a writer. Just as there are some people who don't believe that exercise is working unless it's hurting so much they want to cry, there are writers who don't feel they're learning anything unless their work's being torn to shreds, preferably in the crudest terms. And, equally, some writers know that feedback cast in those terms (including reviews and the like) does so much damage to their confidence that it really hurts their writing. As we learn to write each of us gets to know our writerly self, and it's entirely your right to choose what exposure that self should have, taking into account not only what you can take, but who's giving the feedback.
'This is shit' is no more useful, as feedback, than 'this is wonderful', and it's not more honest, either. And every teacher knows that pointing out what someone's doing well is often just as useful as telling them what they're doing wrong, particularly in humanities and the arts, where the good things may not come about entirely consciously. Brutality is not inherently more honest than gentleness, and if it's painful enough to make the writer to go self-protectively deaf, or to damage their confidence badly enough, it's counter-productive. Gentleness, however, is not inherently kinder than brutality, if it witholds the less palatable truths, and never offers the writer a different pair of glasses through which to see their work, and so never gives the writer a realistic idea of the work's value, or any idea how to improve it. In exercising your right to choose what feedback to ask for, you do also need to think about what will help you most as a writer, even if that means short-term pain, or frustratingly hard-to-hear whispers.
It's perfectly possible, with practice, to give feedback which is honest without being damaging, and kind without being useless, and anyone who's incapable of doing that is probably not someone you need or want to let loose on your work very often. It helps when you all know each other, because people's hearing for criticism varies hugely, as does their pain threshold. And most of us get it wrong on occasions, and most milieux find a particular point - a certain tone - which suits some, and seems all wrong to others. Ann Lamott, in her classic Bird by Bird, says of this issue, 'The sword of truth need not be used to cut; it can also be used to point.' There are plenty of writers knocking around who could do with being told that, but I would suggest that even those who wouldn't dream of wielding a sword in anger nonetheless put in some fencing practice. Just to make sure every gesture they make is clear, sharp, and... to the point.