My concern with Emery early on was that he didn't come in and demand the club shape the squad to play the style of football he wanted to play.
In all honesty, I don't think he would have got the job if he didn't express in the interview process his willingness to adapt and work with the squad we had. Gazidis basically said as much ("evolution not revolution." Arrogant, deluded tit). And there were rumours that Arteta wanted to rip up the squad and build it anew.
That set me against Emery from the get-go. And look what happened: We started off with the aggressive high press, the high defensive line to go with it, and played exclusively short passes out from the back--and it all collapsed very quickly when it was clear we just did not have the players to pull it off. What we've seen since is the devolution into a team similar to Wenger's that neither acts as protagonists, to use Emery's phrase, nor is well coached at sitting deep and organised. There is no identifiable style at all.
I blame Emery and the idiot Gazidis for this. Of course the latter was never going to agree with an incoming coach that 75% of the squad he'd signed were rubbish and needed to be sold. Hence why Arteta didn't get the job. And Emery doesn't have the vision or intelligence, in my opinion, to oversee a revolution like that. Or the confidence and force of personality to demand that of a club like Arsenal. Hence why he got the job.
I don't think he's up to it, but it's do or die this summer for Emery as far as being a manager at the top end of football is concerned. He either obliterates this squad and builds a squad that can play the style he wants or he muddles through with a squad full of crap, fails in similar fashion, and slinks off into obscurity next summer.