Rather than cultivate a friendly and open community, they decided to be hostile and closed. I am not surprised by this at all, but I am surprised with how long the decline has taken. I have a number of bad/silly experiences on stackoverflow that have never been replicated on any other platform.
I don’t entirely agree that more and better documentation removes bugs, problems, questions, concerns, or cuts too much into a 50% drop in site usage. Having documentation is just another tool in the toolbelt, to be used alongside community forums.
Discovery process for myself and many of my coworkers has always been; Look up obscure errors, problems, etc. to get an idea of what I’m dealing with, and then off to the documentation.