Deleting threads should be a very last resort and used as a rare exception. Unfortunately, AZ does appear to be on the exact slippery slope you alluded to and losing traction, as we speak.
Speaking just for myself, I have found myself with less desire to post here lately. I won't go so far as to ascribe that to the increasing gay abandon with which threads are getting deleted, but it has had an impact -- I mean, why bother posting if what you write can just be whacked at someones whim (and whacked without explanation, at that).
I believe that it would be a poor, poor choice to try and keep every post and discussion on this board at the level of pablum. For the most part, people here are adults, contributors, and members of a community -- they are passionate about every aspect of pool and will disagree about shots, strategy, equipment, fundamentals, instruction, and anything else related to the game you can think of. And that is as it should be.
Lou Figueroa