From the many different forums that I've been to, there seems to be quite a few comments that tend to offend other members. As a result, many members who are offended become defensive and appear to be insulted (as noted above). When studying and doing over a thousand questions for the CRNE, this was actually a scenario used for psychosocial questions. I remember a rationale that specifically says "direct" comments can lead to people feeling insulted, offended, and defensive.
Secondly, less experienced nurses who notice that these direct comments are not helpful and non-therapeutic voice their concerns and reasons, yet members who post such direct comments continue their ways. It also seems that such direct members are usually from the more experienced nurses. This is yet another scenario used in CRNE type questions, where a student nurse tells her preceptor that she is doing something wrong, but the preceptor continues without reflecting on what the student nurse said.
Interestingly enough I was able to use these threads to help me understand and remember concepts that the rationales were explaining when doing psychosocial questions.
Although none of these comments were ever directed towards me, as a third person reading them I do in fact find them quite offensive, and I'm sure I am not the only one.