Jumping (in some form) is standard in most 3D games these days. That there is such resistance to the idea out of nothing else other than tradition and a desire to limit what others can do shows what's holding this game back.

If the concern is realism, just have jumping consume Stamina, or maybe give a 30-second "Winded" debuff that disables jumping after using it more than a few times in a row without a few seconds of rest. There are sensible solutions that don't involve sounding like you're old hat.