Can someone explain to me why Warden is so popular when Rook is the better operator?

Probably biased but Rook's ability gives 20hp to all teammates and lets you self revive while half the time I see Warden players die to Blitz anyway. Rook has 1.5 and 2.0 scopes compared to Warden and really the only better thing Warden has is a running animation, isn't french and has a nitro cell.