Trust me, I've been popping in and out of the AvA for many years.
Your "unwritten rules" are bullsquat. Nobody ever followed them. EVER. No matter when I've played, even way back when it was fun (in the "good old days") those rules were just wishful thinking on the part of a select few.
Here's the problem with the AvA: The folks attached to it (like yerself, and myself long long ago) look at it with rose colored glasses.
It is NOT just the past 4 months, because I've barely flown in that time frame. It's been this way for a LOOOOOOONG time. I see an interesting plane setup and pop in, only to find total cherry picking, alt monkeying, gang raping, field hording (as close as can be done without ack interfering) and the like.
There are many reasons you may not have taken notice of this, but for simplicity's sake let's just chalk it up to being carried away in the moment and not paying attention.
I reiterate: This is not a new development!