The move shows they felt that they needed Blount going after him so quickly. I don't hate the play but just saying Blount is never going to be a star running back for any team over a long period of time. In the future he could find himself in the same spot having a game where he rarely or never plays. The Steelers dropping Blount so quickly probably goes deeper then just what he did on Monday night though for them to just snap can him like that. He was probably venting his frustration for a while now bringing negativity to the team if I had to guess.
Blount is a solid play for teams with a running back by committee approach but probably at the bottom of barrel in these situations (all team dependent) and is not going to be happy behind a workhorse RB as Bell is.
I do agree though when it comes to coaching Belichick is GOD and anyone who says otherwise is either diluted or needs to check their hater card at the door.