For. I'm not a CoD expert, but I've played plenty of other online shooters to have a strong opinion about this.
In a metagame way it makes sense to do. Sure it's not realistic, but then most shooters aren't realistic to begin with. And that's not even the point. The point is it's in the game, it's not cheating, and if you think it helps your play then you'd be stupid not to use it. If the devs thought bunnyhopping shouldn't be done they'd have put some kind of mechanism in place to prevent it.
If you don't want to jump because it's so much more unrealistic than respawning that it ruins your game, go ahead. But pushing your beliefs on others who do know how to make the most of their game is petty and stupid. It's like those Street Fighter players who tell you using projectile attacks is unfair. No it fucking isn't. You're just a lousy player who can't deal with that part of the game. And bunnyhopping is (usually) far less important to shooter gameplay than projectile attacks are to fighting games, so there's even less reason to whine about it.
All I have to say is: Learn to play the game.