Wyliec et al, if a 'borderline' thread is 'recoverable' by removing one or even maybe a couple of posts, then that's the preferred option - and that's what happened to your post Plarimer, so don't think this one is (entirely... ) your fault.
However, when a thread starts out heading 'borderline' then the first few posts/responses (that were otherwise fine) serve as the trigger for others to go even further and take the discussion into areas that are not allowed here (I would've thought for obvious reasons!) at times there is no clear way to defuse that apart from closing the thread, which is what would normally happen, as you've noticed before and mentioned wyliec.
But when more than one of those 'going even further' posts refers back to earlier posts & takes the whole thing to an entirely different level of rule breaking & posting that goes well beyond 'borderline', then in the interests of protecting the Forum and all the posters NOT involved in turning that thread &/or the whole Forum into an offensive all out brawl, there's every likelihood that the thread will be deleted - and it was!
Remember, the Mods are here to try and keep the Forum a friendly, helpful place that's easy to use, ask questions (about Spyders/Rykers etc) & share knowledge &/or experience place for anyone with an interest in Spyders &/or Rykers; the Forum IS NOT here as a venue for political, religious, or any other type of argument that you might want to drag up - there are other places where you can do that, but they are NOT HERE!
That said wyliec, you knew going in that your question & its implicit involvement with many of the political & ideological 'discussions' going on atm meant that the thread had the potential to be de-railed and head down a path that wasn't ever going to be allowed here, even tho the early responses/posters did try to stick to the topic! But the question itself and those same early posts also raised points and used words that could readily be used to drag it off track & into areas of discussion & argument that are not permitted here; and that's exactly what happened! So all up, given that the question and the earlier responses, while they were sorta OK in their own right, were the triggers for the thread heading down that 'not allowed' path, a decision was made to close & remove the entire thread!
The Mods discuss these sorts of things, usually before but sometimes, due to the nature of the issue, afterwards - regardless, any decision re closing &/or removing threads is subject to consultation and discussion within the Mod Team. So just like everything else, this particular thread was discussed and collectively, the Team that's been appointed to oversee the Forum & posting behaviour decided that removing the thread was the most appropriate response. The posters involved in dragging it off track know exactly what they did & who's to blame for its removal; just as you wyliec, know that this particular subject at this particular time was always going to be pushing the envelope a little and was likely to end up being moderated, potentially closed, or maybe even removed. Is it so surprising that it went the way it did?!