Note that bounzer doesn't not destroys the monster after negating it
Don't start thinking that 1 negate will win you the game on its own. If that were the case witchcrafters would be invincible
Most of the time, unless you're negating a non-OPT effect (which is rare anyway), that 1 negate can completely change the game even if the negated monster is not destroyed.
The entire point is that you delay your opponent's plan, giving you a chance to strike back and win the duel.
1 negate is not that good anymore, most decks have second plays beyond that: thunder dragon, lightsworn, desperado (well they don't care as long as their machines get destroyed), nk, even sylva s and blackwings.
Witchcrafter was meta because of the absurd resource recovery they had + mill/genni/Patronus. Bounzer doesn't add to your hand 4 cards during the end phase