I don't think people were expecting a massive turn around though. Most sensible people agree that 7th/8th would be a perfectly acceptable return this year, nobody's asking him to win us the league.
The fact is, we're currently 9th and it's a totally false position on current form. 1 win in 11 games is horrific by anyone's standards. I don't want Koeman sacked and I don't think he can be - yet. Seriously though, if we don't win any of the next 4, relegation becomes a genuine possibility. Sides that only win 1 game in a third of a season quite often go down, and don't think it couldn't happen to us.
I don't care who the manager is, or how long he's been here, a run of results like that is simply not acceptable. Taking over a team who finished 11th, adding 5 players of your own and going backwards is not acceptable. Call me deluded all you like, but unless he starts winning some games quickly the manager will be under massive pressure, and rightly so.