True pushers almost never hit winners. They earn all their points by bumping the ball back into play and watching the opponent make an error.
So the opposite of a pusher is a player who hits a lot of winners. In the past, I'd say that S&V is the most opposite of pushing. S&V players end up getting passed or hitting winning volleys. In the modern game, a player who hits hard to get winners is the opposite of a pusher, even if they stay at the baseline.