It's pretty safe to assume that guys who get 120+ in a season are doing something right
It's still a stat entirely dependent on teammates. A guy with 120 ribbies is doing something right but he's only getting the chance to because of what his teammates are doing. I remember when Ryan Howard signed his massive deal with the Phillies there were tons of articles lambasting it. One of them I read was talking about that despite four seasons of 130+ RBIs he wasn't all that terribly efficient at producing them. In fact, David DeJesus of the Royals was about as efficient at knocking them in, despite having half the number.http://www.nytimes.com/2010/05/02/sports/baseball/02score.html?_r=1
Similarly, Howard’s mammoth R.B.I. totals stem from the on-base skills of the batters preceding him. Over the last four years, 1,993 men have been on base for him, the highest figure in baseball. During that time, the Kansas City Royals’ David DeJesus has driven in a similar percentage of runners, with 18.3 percent to Howard’s 18.8 percent. But because DeJesus hits leadoff for the lowly Royals, and Howard hits cleanup for the mighty Phillies, DeJesus’s R.B.I. totals pale in comparison.
And of course the classic example of the misleadingness of RBIs is Ruben Sierra's '93 season.