Whatusaytomesaid: I say keep it. It's basically a white portal for the entire map. Entirely safe and optional. Basically the best option for PvP the game has.
If anybody wants to duel, let them, if you dont want to, just don't. Pretty sure you can toggle off challenge requests, right?
I can imagine the attacks and hit splats making potato computers laggy, which could be the only real argument against it.. but people with good computers just expect you to upgrade instead of putting it on Jagex. So assuming the same here, it won't happen based off a lagg argument alone.