I happen to like the airlines that I fly with, and freely comment if I think things need tweaking (defective IFE, defective seats, defective CC <heh>). I find by replying I see two things:
(1) It often gets something done about it, and
(2) It often gets rewarded by the airline.
I'm no longer the eternal optimist. With BA you either get a boiler-plate reply and insincere apology or silence.
Deep inside, I suppose, I keep hoping that BA will return to the former standards but reality kicks in - they have gone past the point of no return. I no longer see them returning to past glory (or whatever). I was gold, now silver and heading for blue. Their loss.