I think it's fair to use some sort of expected success rate when looking at YPC (a RB who goes -1, 1, -3, 2, -4, 0, 50 isn't generally the kind of player you're looking for), but not taking into account context (goal line, short yardage, 6 or 8 man box, etc) means that it's impossible to praise or to criticize a player for putting up 3 yards on most runs.
Michel is a good player who is only getting better. He should put up over 1000 yards rushing, and I think he'll integrate into the passing game a bit more as time goes on -- in fact, I suspect we'll see about 1400 total yards from scrimmage and around 10 touchdowns by the end of the season.