1.) It's the only type of CC your idiotic teammates can't break with AE damage. As I actually play high chloro in PVP this is my most effective CC, as bad as it is. Fears and trans constantly get broken by teammate damage.
2.) I could care less about the snare/knockback/root DR. If it gives me distance it's worth the DR anyway.
3.) Hilarious to troll teammates in 5 v 1s by prisoning the 1.
If anything the main handicap to this ability is the ridiculous 2m cooldown. Because of the charge mechanic and the double DR it's already very situational and then having to worry about a fail dodge or a riftwalk/break free simply burning through the 2m cooldown is just brutal.