Corbin through him under the bus by telling the media that the Marvin lineup gave the team a better chance to win, than the Kanter lineup. How did he know this? A lot of variables switched at the same time. Trey, Marvin and Jeremy came back from injury, giving a serious jolt to the quality of players in rotation. And the schedule went from being the hardest in the league, to being one of the league's easiest when we started winning.
Marvin came back on 11/22 and immediately played 32 mins his first night back. Kanter played 32 mins the night before, and immediately played 21 mins on the night Marvin came back, then Kanter got injured in the OKC games on 11/24, didn't play in the CHI game on 11/25, and by the time he returned on 11/29 to face PHO, Corbin was rolling w/ Marvin, and Kanter's minutes were to be bounced around for the rest of the season.
You ask whose minutes should Kanter have taken? The answer is obviously Marvin.
Compare their splits:
https://espn.go.com/nba/player/splits/_/id/2797/marvin-williams
https://espn.go.com/nba/player/splits/_/id/6447/enes-kanter
Now per 36:
Enes Kanter- 49 FG%, 73 FT%, 3.7 ORB, 6.3 DRB, 10.1 TRB, 1.3 AST, 0.5 STL, 0.7 BLK, 2.4 TOV, 3.9 PF, 16.6 PTS
Marv- 44 FG%, 36 3PT%, 78 FT%, 1.8 ORB, 5.4 DRB, 7.2 TRB, 1.7 AST, 1.2 STL, 0.7 BLK, 1.1 TOV, 3.3 PF, 13.0 PTS
By all accounts, Kanter can stretch the floor, but was not allowed to under Corbin. So saying Marvin starts because of floor spacing isn't fair. Starting Marvin at PF made Favors have to play the 5, where he was a lot less effective. Marvin was also abused by most PF's he'd face. It's no wonder we were the worst defensive team.