Mac is making the right read most of the time. The OLine SUCKS where it's 4 Olinemen and a crappy right tackle. When you have zero time to throw the right play is get it out fast, a lot of short passes. Mac has a beautiful deep ball but it's not worth taking a viscous hit 9 times a game just to get your overrated oc his next HC job.
Having said this, it's also true Mac needed a year to get his body NFL ready. This is why him learning for a year wasn't a bad move, we're throwing the kid in when his body could have used a year to develop (and also work with Tom House). Was saying in pre-season he had to put all his body into throws to really get zip. It's not a huge problem as he has a great arcing deep ball and most other throws don't need to be bullet throws. He has excellent timing and anticipation. Mac can make all the throws. His arm strength is not the reason for the short passing game, it's the crappy OLine giving zero time.
Mac's arm strength isn't to blame for a ton of short quick throws, this is the right read when your OLine is total garbage right now. If skippy keeps calling shotgun but the OLine sucks, the right play is a quick throw. Mac is doing the right thing. It's not because his arm strength is insufficient because the fake-expert construction worker guy said so.