You are saying two things, first its the fault of the rest of the offensive players and second it is typical for a rookie. Which is it?
All I am saying is lets call a spade a spade. Was there lack of talent? Yes, Were their drops? Yes. Was the lack of talent and drops the main reason for completing low 50%? Nope sorry that is not what I saw. Yes his % would have been higher without drops. But all QB's have drops so the question is how many more drops did allen have compared to others. Josh Allen was often late on throws and as a result through into traffic, sometimes (more often than is typical) just misfires, and is generally not good at short passes, screens in particular. I am not saying Josh Allen is a bust or anything, just being honest with what I saw.
Like you said, it is not atypical for a rookie to have some bad numbers, it does not predict the rest of his career or anything. But he has a lot to improve on is all I am saying. Anyone who thinks the guy is as good as Mahomes and he just needs talent is ridiculous (I have seen that a lot here).