There's a lot of good sense in this.
Personally I think it's not unreasonable to benchmark to a previous season, but there does out to be some context.
The lumpiness has to be factored in as stated. Id also add
1) We didn't have a lot of injuries, this season we have
2) We lost a lot of players, and are one of the few teams to have a net transfer profit
3) We won a lot of games by a narrow margin last season.
4) If you factor in the 2 prior seasons, we have 39 and 36 points. That's probably a bigger, and better data set than just last season.
Which point above people wish to give most weight to is open to discussion, and honestly I don't have enormous preference. But in each has to be factored in. I remember under Moyes, we would win a lot of games narrowly, then lose a lot of games narrowly the following year/season. It wasn't that he was an inherently inconsistent manager, but the margins he was working to are fine.
There seems to be an assumption we have a strong squad. I personally don't see that. I remember seeing Fulham at Goodison recently, undoubtedly well coached, but thinking probably 7/8/9 of their outfield players get into our team. And without being disrespectful to Fulham, they are not one of the traditional big 6, or Villa/Brighton/Newcastle who seem to be the closest challengers. They are a mid table team, and their squad looks far better than ours.
