In today's NFL sitting QBs and allow them to learn from the bench is a luxury that most teams/HC can afford because of coaches being on a short lease, teams wary of giving a QB a franchise type QB contract if they haven't earn one etc. Instead it's prove you can play or we find someone who can. TBH I think Josh being forced to play his rookie season accelerated his development as we were able to learn his strengths/weaknesses sooner than later and then surround him with the talent he needed to produce.