Think in a lot of respects Villa must be the most challenging job going. The expectation is completely out of tune with the historical record for the past hundred years. 100 years, with 2 FA Cups, 1 League championship, 1 European Cup.
However, you ask any Villa supporter if finishing 6th is acceptable as being a long term aspiration, you'll get given a short, sharp "no". With some justification - the West Midlands is the 2nd most populous region in the country, and Villa are the biggest, best supported club by some margin. There's no clubs of a similar size for miles around, maybe Wolves compete with us for fans to the west, Leicester & Nottingham Forest perhaps in the east - but going north it's 'our' territory up to Stoke or Derby, and southwards there's nothing until you hit London.
The expectations will vary between supporters, but you're not going to get less than 'win the league cup every 5-10 seasons', and most will extend to winning the league with some degree of frequency. I can't think of another club where winning the league every 30 years would be seen as a failure when the club has taken 110 years to win the last 2. But if we're all honest, had we won the league in 1989/90 or 92/93, we'd all expect to have won it again by now.
There's only a handful of clubs where that level of ambition/expectation is held by the supporters. Excluding the nouveau riche :- Manchester Utd, Liverpool, and Arsenal. It's that level of job, but without the historial record to back it up (at least within anyone's living memory).