Perhaps, but they sure leaned on him when it came to big games (see Michigan and Florida as examples). It would be pretty crappy to short-change him playing time for those reasons, and then to ask him to carry a larger burden when your win-loss record was on the line. But I am sure coaches have done crappy things before.
To the larger point about Ferentz playing less talented players over better options, there are certainly some prime examples we can point to. But since I think you are one of the most reasonable and balanced posters on here, I think you would be willing to consider this: talent is part of these decisions, but the coaches are also dealing with human beings. Human beings who might need the proper stick or carrot to achieve their full potential, depending upon a given situation. Human beings who make up a collective team whose chemistry is impacted if a deserving veteran is passed up by someone younger not based upon production, but on potential. This aspect makes the decisions much more difficult. Perhaps it is true that Ferentz bungles them more than his peers, but there might also be more to the situation than we sometimes see.