Why on earth would police enforcment use airsoft rifles? Are they going to annoy rioting protesters with tiny little pops? Most tactical law enforcment agencies use less lethal rounds like beanbags, rubber bullets, and gas. The former two being pretty much like actually getting shot.
And the only thing you say that airsoft holds over paintball is that its more tactical. You have clearly never played paintball with 2 sergeants that were off base for an afternoon of paintball.