You make it seem as if people want to forbid jumping. I have not seen anyone ever post this on these and the old forums. There is a HUGE grey area between this mess we have now and exploiting jumping (up to influencing the netcode) and no jumping at all.
Giving some stamina cost to jumping makes sense, because it would add more skill and tactics into the movement overall. The values can even (and probably should) vary between out of combat and in combat. It would be a lot of progress if the 360° jump with full speed range would be stopped as well as combojumping. These are hard game effects, not just "annoyances".
If people jump over obstacles or manage to "dodge" attacks, still fine to some extend. But nothing in your arguments speak against giving jumping some drawback.