This seems to be the main point that you're missing. Ever since Morris went down, Maroney's production has dropped drastically. Could it be because Maroney lacks the toughness to be the premier back by himself? His lack of production in recent games, plus corroborating reports that the coaching staff questions Maroney's toughness lead me to believe that Maroney is on shaky ground. Maybe it's easy for you to rely on blind faith alone, but the numbers paint an entirely different picture of Maroney and the Pats RB situation. When it's 3rd and short who gets the carry? More often than not it's Evans, Brady, Faulk or Eckel. That tells you a lot right there.
Some people just have to piss in the punch bowl and ruin the party for everyone. So, yet again, here we go:
Week 01: Jets (26th), leading rusher is Maroney w/72 yards on 20 carries
Week 02: Chargers (21st), leading rusher: Maroney w/77 yards on 15 carries
Week 03: Bills (21st), leading rusher: Maroney w/103 yards on 19 carries
Now, during these 3 weeks, the Patriots were splitting most of the carries between Morris and Maroney, for totals of: 37, 32, and 38 carries by the team. In all 3 of these games, Maroney was the game's leading rusher
Maroney gets injured
Week 04: Bengals (21st), leading rusher: Morris w/117 yards on 21 carries
Week 05: Browns (30th), leading rusher: Morris w/102 yards on 21 carries
Week 06: Dallas (7th), Morris has 14 yards on 10 carries
Morris gets injured in Dallas game
Now, during these 3 weeks, Morris was a featured back. The team ran 34, 32, and 29 times. Morris feasted on two bad running defenses, but got only 1.4 ypc against the first decent rush defense the team had faced all season.
Maroney returns
Week 07: Miami (26th), Maroney gets 31 yards on 6 carries (5.2 ypc)
Week 08: Redskins (7th) Maroney is leading rusher w/75 yards on 14 carries
Week 09: Colts (14th) Maroney has 59 yards on 15 carries
Week 10: Bye
Here, in these 3 games, we see Maroney taking limited snaps but being very effective in the first two games. In fact, against the league's #7 rush defense (Washington), Maroney puts up 5.4 ypc and is the game's leading rusher. The team rushing attempts (22, 35, 28) are sensible given the teams faced and the strategies employed. Miami, for example, saw it's safeties drop like flies, making running the ball a needless exercise, particularly in Maroney's first game back.
Week 11: Bills (21st), Maroney gets 19 yards on 6 attempts
Week 12: Eagles (5th), Maroney gets 31 yards on 10 carries
Week 13: Ravens (1st), Maroney gets 44 yards on 13 carries
These 3 games are the only games that anyone should even question in the slightest regarding Maroney and, in fact, it's only the Buffalo game that should truly lead to questions. The Eagles and Ravens are two of the best rushing defenses in the league, so throwing the ball more in those games makes sense. This is particularly true in the case of the Ravens, a team that's putting up historic numbers against the run. The one questionable game against the Bills is the game where a public situation arose, with the team reporting a Maroney injury and Maroney denying he was hurt. As members of the public, we don't know what happened here: miscommunication, Maroney telling a fib, a minor 'tweak' being blown out of proportion, etc... We simply don't know. For the record, New England ran 29, 16, and 24 times in the three games. Also, for the record, when New England played the vaunted Vikings rush defense last season, with Dillon and Maroney, they only ran the ball 15 times. Clearly, limiting the number of rushes against a strong running team is not a foreign idea to BB and the team.
Week 14: Pittsburgh, ?
Pittsburgh is 3rd in the NFL against the run, so it should come as no surprise if the Patriots take their game to the air again and eschew the run.
So, to sum up: Maroney has played in 9 games, including the Miami game which was a clear case of getting him just a couple of runs to see how he was able to handle game contact again. In those 9 games, he's been the game's leading rusher 4 times. Now, given that the team was clearly not going to focus on the run in the Eagles or Ravens games, and given that the team was behind in the Colts game, that cuts the number of 'rush friendly games" down to 6. If you then remove the Miami game (1st back), you get a situation where Maroney has been the game's leading rusher in 4 of the 5 games you'd have expected his running to be a factor, and only the second Buffalo game stands out as unusual.
Does this show that Maroney is an elite back? Absolutely not. What is does show, however, to those who actually break down the games rather than just blindly pursue an agenda, is that Maroney has been fine for the team. He hasn't been a 'bust', and he's tended to get the job done in most of his games. Wasting a pick on McFadden is a luxury that a team with needs on the OL (this team really needs a dominant tackle) and in the LB corps (and maybe the CB position as well) simply can't afford.