I haven't read the posts others have made since this, so it may have been said - But Barton's tweeting is a case of the straw that broke the camel's back, although I hate that cliche.
Since he joined the club in 2007, he's been involved in assaults, been put in prison, had numerous spats with players on the field, fell out with Alan Shearer, made disrespectful comments about the board at after dinner speeches, and probably some other things I've not remembered. Despite all that, I still want the guy to stay, but Ashley deserves some credit for sticking by him when most owners would have hoofed him out long ago.
And yes, there are plenty of things the club could do, and have done, that I don't support. I didn't like the way they treated Keegan, or Shearer, or Hughton. I don't like the way they handle communication with the fans, and how, when they do speak, they often mislead us. I think as far as owners and general club managers go, they're terrible.
Despite what you might think I'm not some blind Ashley/Llambias follower, but I'm also not as deluded as you are that I'll blame everything on them with little regard for the truth and facts.