Qwiss Basically the conversation has gone from "it's only the Portuguese league, he'll never get those opportunities in England" to "he's not sharp enough when the opportunities come along." Which, to be fair, isn't an unreasonable criticism, but I do think it says something positive about how quickly he has found a way to contribute in the team.
He's performing better than the other players people wanted to break transfer records over this summer, and that's despite arriving unfit in a new league, having an extremely tough fixture opening and being forced to start every single game. Has anyone in the squad aside from Raya played as many minutes? There's been no complaining, no cheating in the pressing because of tired legs. He plays ever three days and keeps running both centrebacks ragged. Warrior performances.
Like you said he could easily have taken the penalty against West Ham. If he'd gotten the penalty call against Newcastle and the shot against Olympiakos had bounced off the post and into the net instead of serving Martinelli with a tap-in from two yards no one would be complaining right now either. When margins are that fine you just need to keep doing what you're doing because it'll pay off eventually. We're top of the league right now and it's clear Arteta doesn't seem to think it's in spite of Gyökeres.