I can see that to an extent, but like with Grossman's bad days and him being left in there to be sink or swim it can be taken too far and all you're doing is training to be bad.
I like the "old" days where you put your young QBs in garbage time not to just hand the ball off but to play. If they started throwing a game away you put the starter back in. Of course the Bears would have to have a valid starter to do that.