I'd set myself the task of not posting anything until the new APLT thread opens up, but I've been sucked in...
To me it seems as though some people are confusing two different things, 'negative' posts and 'negativity'. I have some sympathy with SP's argument that threads are diverted into discussions which are nothing to do with the thread. I've stopped reading the Paul Tompkins thread because most of what's said on there now gives you the impression that the posters haven't even read the OP or the Tomkins article. To some extent...that's what's happened in this thread too, but it's not getting us any closer to the confusion between negative & negativity. The mod's do drag discussion back on-topic from time to time, or even lock threads that have run their course...which is no bad thing.
Personally I don't see anything wrong with posting something which is 'negative', I've done it myself (or at least, something which I've thought as balanced but others thought were negative). I'd defend myself by saying that I try and present it within a reasoned argument (mostly). I don't detect that the majority get pissed off with 'negative' posts if it's presented as a reasoned argument. It's quite possible to hold a negative view on one issue and a positive view on a different issue. Such individuals views tend to aggregate to an acceptable middle/ balanced outlook.
Negativity is a different thing, at least I think so. That's the basic disposition to view each issue/ prospective outcome in a negative light. In essence they don't have what most of us would regard as a balanced view. This comes across as them driving an agenda. With no sense of irony, they are the usual subjects in here who are agenda driven and who themselves use that epithet as a label to dismiss people who disagree with them...and they're not necessarily always the ones we'd think of as 'negative'.
Another thing which has been called for is a sense of moderation in arguing/ discussion. Some people don't help their own cause with this... A page or two back one contributor, making the case for moderation, described having to read this constant negativity as "...abject misery..." Abject misery...really...? I'd have thought that trekking bare foot over snow covered mountains to escape murderous bandits was a bit of a piss off, sitting cold and hungry exposed to the elements beside the earthquake ruins of your home was a tad inconvenient but sitting in your warm home, sweet coffee in hand reading something you don't need to read is apparently abject misery.
In short, the call is for each of us to stay on topic, argue with balance & moderation and not promoting an agenda. I can't see who could argue with that.