There's nothing as pained as topping the table from the early start of season, and giving up to your preeminent rival, specially when the league is coming to an end. Mikel Arteta and the teammates are devastated by the fact that they were so close to accumulating the Premier League trophy. The Gunners played incredibly well in league games, but they were eliminated from all European events, hoping to compete in the English Premier League, which they were unable to do due to exhaustion. Mikel Arteta will not relent on his job any longer; he will sign more backup players for his important players in the squad, as injuries continue to plague his squad.
Arsenal can blame no one but themself for losing the title this season. They played really good football around the half of the season. But as the season end was coming closer, their form started dropping which made them lose the title in the end. Man City is a better team and it is only fair that they have won the title. Arsenal simply didn't deserve it.
Well, indeed, Arsenal messed up big time, I personally had high hopes for them, like I said in one of my previous comments, they really played well and made everyone believe they were right on track to winning the title this season, and like you said, just when the game began to hit up that they were supposed to start playing their best, they slacked and started losing matches, ones they don't loss, they manage to draw, this is where and how their failure came about.
Right now, I only hope they go back to their drawing board and see what they must do, so as to do well in the champions league next season, alot of eyes are on them.