The thing is we are not trying to develop players for a future, we are trying to make the playoffs, and despite his recent slump Herrera is MUCH better than Moniak (actually, almost everyone in the majors is). Moniak simply cannot hit ML pitching, it is incredibly obvious, maybe someday he will, but it isnt today and having him flail away at guys he cant even make contact with isnt going to help. He needs to be in AAA working on mastering those pitchers and learning how to hit better pitches, particularly breaking balls. I dont want him sent down to punish him, I want him down because he hurts the team and it destroys his development. There isnt much chance he will flourish, but the only chance he has is at AAA right now.
Keep in mind we dont have infinite time to send him to AAA. He is going to be out of options after next season and he still has quite a ways to go to be viable as a ML player.
He didnt hurt much tonight, but he hurts every single game he plays. He actually has not had a 2 hit game yet in 44 games in the majors, that is freaking amazing.
If he hadnt been a #1 overall pick they would have given up on him a long time ago, there just isnt much to think this will work, but it is hard to just give up on a once a generation pick.