I don't think it's fair to say he had "all the pieces around him." The receiving corps was very young - Burbridge and Kings were freshman and Kings didn't really produce. Lippett was only a sophomore and was still developing, same with Mumphrey. Arnett hardly saw the field. Fowler, a junior was the only upperclassman. And that future record setting NFL running back was held under 100 yards (really under 80 yards) by 5 teams that year. Sure he put up sick numbers against shit teams like Minnie, BYU and EMU and had a great game against Iowa (2-6) and Nebraska (7-1 with a very soft schedule, getting their asses kicked by the only good team they played) - I'm not saying he wasn't good. He was definitely one of if not the best back in the B1G.
The defense was very good (despite Johnny Adams' inability to cover anyone) and again, Bell was a top B1G back but Maxwell was not the only weakness on that team. The offense was very one-dimensional and the o-line was overrated as evidenced by the fact that good teams were able to stop Bell. We were 95th in total offense - that's not all on Maxwell. It's more accurate to say Bell was the only good part of our offense than Maxwell was the only weak part of that team.
You probably think I'm saying this just to disagree with you so if it makes you feel any better, on balance the 2012 team was better than 2016 but to say Maxwell had all the tools around him and he was the only problem isn't true. A reasonable case can be made for TOC being worse than Maxwell.