… why? What possible advantage does knowledge hoarding offer?
I agree with all your general points but I also understand from where AZed is coming. It's not hoarding that's on point here, it's signal to noise.
Imagine someone posts the most mundane Perl question on SOPW and I answer with something awful, dangerous, etc. How long will my post go uncorrected by another monk? 10 minutes? An hour? Maybe a half-day if it's a weekend and the original question was overly verbose. What if I respond in a seemingly reasonable and forceful rebuttal making my answer seem more correct? How long till I'm dogpiled by better answers and further corrections from a few other monks? It's not a hoard here as much as it is a pure vein.
I visited StackOverflow a couple of days ago and started to reply to a Perl related question. Then I reread the 10 wishy-washy, naïve, 100%-opinion answers that were already there and I said to myself, Ah, f*** this. No one is going to be able to see the pearls in the mud. It's the same reason I think I've been to /. 3 or 4 times in 11 years of being online all day.
Seeing your OP here, however, makes me strongly reconsider spending time over there. Knowing other monks might be there definitely changes the lay of things.