Or he could have just James Harden'd him like Scott Brooks did in OKC.
If Scott Brooks had started Harden from day 1 like he did with Westbrook and Durant, they might have won the NBA championship in his third (and final year) and maybe they would have realized that Harden was the better player than Ibaka and gave him the extension instead, and kept Harden/Westbrook/Durant together.
Obviously, I'm not comparing Harden to Nesmith by any means, but it's just unknowable to say "Brad benched him, he came back playing good, therefore, benching was the right decision." It could also be "Brad benched him, he came back playing good, Brad fucked up by not playing him more while the team shit all over itself for the season."
Honestly, I haven't heard many arguments that "less minutes equals good development" before the Nesmith discussions around here. If the Angels had kept Mike Trout riding the pine for a couple years, and then he turned into Mike fucking Trout, would we all be lauding the Angels management on taking it slow with him? Or would we be wondering what the fuck the Angels were watching and seeing by having him hang around on the bench? Brad didn't take it slow with Tatum or Brown or Smart like he is with Nesmith, and those guys all had a bunch of rough nights early on, so why weren't we blasting Brad at that time for giving the rooks too much run when they needed time to develop on the bench, even if they were better than the guys in front of them (like Nesmith is with Semi or Grant).