I wonder why diagnosing anyone on a public forum should be allowed under ANY circumstances. On other forums the policy is that no one can give anyone a diagnosis or professional advice and that makes perfect sense to me because forums are not intended as a substitude for therapy. Why there is no such policy on this forum? Is this not a liability issue after all?

As for the rest, it is not really what is said but HOW it is said that makes a difference in terms of posts being supportive or judgmental. It is the intention behind the words that makes all the difference.

Unfortunately, it is difficult to come up with a well-defined objective criteria of what is and isn't supportive, and, so, IMO, it is moderators' subjective call to make that kind of judgment based on the specific situation.

Their decisions, however, should be transparent and clear to everyone here IMHO. If they want to make it a safe place, sending private messages and making people disappear quitely would not help. It'd do the opposite. It'd make people more anxious and confused about what's going on here, as they wouldn't know why certain people were banned from posting.

If the thread becomes contentious, the healthiest way to deal with it IMO is to address the specific problem right on the thread in a timely manner so everyone could see and understand the moderator's position, and this is how things are done on other forums.

Vague, generalized definition of what is and isn't supportive doesn't give anyone clarity of what is and isn't appropriate to post. It cannot possibly give that clarity because judgment and support are rather specific to each situation. Therefore, it'd be more helpful if the mods addressed SPECIFIC problems on SPECIFIC threads PUBLICLY rather then making people disappear quetely without explaining what's going on to the rest of the forum because that secrecy woud create tons of confusion and anxiety for other members.