Why don't more players play defense like Bruce Bowen?

To me defense is all effort. You don't necessarily have to be naturally good at it to be a great defender, but rather put in the effort. I loved Bruce Bowen cause he would put in so much effort on the defensive end, to stick to the player he was guarding, and not make anything easy whatsoever. He was an amazing perimeter defender. Why don't we see more defenders like Bruce in the league??