The issue with the play is it functions like ZEB right now, except the LBs and dline are packed in much closer with tighter angles to the QB, and the tight packing gives the dline better starting points against the blockers. The lbs can reliably reach the QB a few ticks sooner than any other pass blitz because of the starting positions. The dlines positioning gives them enough advantages to reliably break a guy through relatively quickly on most downs. Like all dual OLB blitzes, the QB has no option to roll away from the pressure. Only elitely built pass blocking olines manage to get a block on 5 defenders even semi regularly. Combine with a high pocket awareness build, you sometimes manage to get all 6 blocked by holding in a back. Its a very rare deal though. Thus, MO is the overpowered blitz because it gets more defenders to the QB sooner than any other blitz more reliably. It also gives up very little on the inside run, destroys counter plays, and even defends a decent number of pitches effectively if your defense is built pretty well to take advantage of it.
this leaves an offensive coordinator a very, very limited selection of passing and pitch plays to counter it. Plays the must run exclusively, for if they don't the tfl/sack showboat parade will curbstomp the offenses morale to the point even the good plays become unreliable.