It's not bunny hopping, let's get that out of the way.
Bunny hopping in a game is when you jump for the purpose of moving faster. It's done because the acceleration of jumping and crouching in a zigzag pattern causes you to move faster, and makes you a smaller target. The point is that you ultimately move faster, and create a harder to hit target. Here's a
quick video that shows what bunny hopping is.
Please note,
Defiance does not have bunny hopping.
What you are describing is people simply spamming the jump button because they think it makes them more evasive. The fact of the matter is that jumping simply makes you more predictable and easier to hit. The better PvPers I have come across tend to run around their targets in circles at close range, and pivot often to confuse them. Arguably the best way to "juke" while in close range combat is to move
around your target and not in front of them. Force them to turn and adjust their aim, then pivot so they cannot have a smooth mouse movement to track you. Jumping just makes you move in a predictable vertical pattern, and you're much easier to track.
That's not to say jumping doesn't have strategic advantages. Jumping over someone's head is a great way to disrupt aiming, as is jumping on a pivot. There's also the fact that you need to jump over obstacles in the PvP maps, and on to ladders.
If you can't hit a jumping target, then I do not know what to tell you. It's part of the game, and a legitimate evasion strategy. Movement and positioning is a staple of the shooter genre, it means just as much as aiming. However, the game
does not need to have jumping removed or neutered simply because people want a homogenized, boring experience. I'd rather not remove features that distinguish great players from average players. If people simply stood and fired at each other, like some sort of
ridiculous line formation, this game would become stale fast.