No, no. Better to assume with absolutely no evidence that Jason Garrett was just a terrible person who wanted to keep Moore down even though Moore would tell you the opposite.
Truth be told, having Garrett around may have had a hand in inspiring Kellen.
KM seems like a guy who can not only learn from anyone he works with, but also filter through what they do and don't do well. So he likely learned a lot from Garrett, and I don't believe it was all bad.
Garrett was rigid and would have no change, but he did treat people well. He seemed to love the players and they love him, but he's the last of a dying breed. Those old school coaches who couldn't change with the times.
So it is great now to have a head coach, who like someone mentioned before...empowers his coaches to bring their creative energies to the table. Mike is a touch old-school guy but seems to have recognized his football mortality. You can't be rigid, you can't win by doing it the same way it's always been done. He's a trusting delegator, motivator, communicator, and most of all a "credit giver". Things that Garrett just seemed to be really bad at.