With non-lethal ammo, it could probably be used in riot situations. It certainly has the fear factor.
Set up like in the video I think even 180 sandbags hitting you instantly is going to present some health issues. Ever see the bruising from some of the "non-lethal" ammo?
Even if they slowed it down and swept a crowd with rubber bullets there would be a higher body count than with aimed shots.
Plus it looks like there's a cost issue, once it's fired it's done. How many millions would it take to supply and then resupply police forces?
I think it would make sense to air drop some to a military out post that is under threat of being overrun but it's overkill for use against protests.