Yes Sledger is spot on. Emery has given no particular reason to believe he is capable of turning things around. Have been thinking about it a lot in the last month or two and in his 51 Premier League games I reckon he's had about 8 that were encouraging. Of which I'd include a 1-1 against Liverpool, a 1-1 at Wembley against Spurs and a couple of thrashing of Fulham. So not exactly setting a high bar. His league record with Valencia and Sevilla is solid enough, but not particularly spectacular. Is a fourth place with Sevilla five years ago enough reason to believe Emery will soon start to suddenly get lots more out of a completely different squad, in a different country, when he has so far catastrophically failed to do so? I find the whole complaining that this is a modern football phenomenon really tiresome as well. As mentioned in basically no other profession would you be allowed to get paid millions, do a bad job, and just be given a chance to get better on nothing other than a hope. It's actually football that's always been the oddity in that sense, and it's now become more realistic.
Edit: I mean I really can't stress enough that in his time at Arsenal Emery hasn't excelled in basically any way. Team is worse defensively and in attack. His man management of individuals has been bad. His team selections suck. No individual player is playing better now than in their first few games under him and loads are playing worse. I can see why non-Arsenal fans might think it's a little bit harsh because at face value results weren't terrible last season, but the people who really engage in Arsenal every week are absolutely unanimous in this. I think purely in terms of performance relative to the strength of a squad, Emery has been the worst PL manager in the last season and a half. Maybe one of the Fulham managers last season would be a rival contender, I thought their squad was miles better than relegation quality, but that's about it.