This legalization has a deeper basis. Forums exist for the exchange of information and, ideally, for the search for a new common truth. If all kinds of off-topic discussions and spam directly interfere with this main goal, "cluttering up the airwaves," then flame (especially subtle trolling) actually helps. Flame rather distracts some participants from the main line of discussion when they take what is said personally, get offended, and start "slinging mud." But the point is that such participants cannot maintain the main line of discussion anyway, with or without flame, so flame works more like a litmus test.
Therefore, creating a special "Preserve" for flame will help to better understand in the long run who is capable of what.