Needless rapelling? It is a way to get down from the cliff quickly.
More and more, it is turning out to be a way to get down the cliff too quickly. Since the proliferation of rappel anchors, there has been an explosion of rap accidents, including very experienced climbers.
In the case of Betty, it is questionable whether there are, in general, any significant speed advantages.
Moreover, rappellers get themselves tangled up with ascending climbers, often create unpleasant clusterfucks, and drop ropes and pebbles, if not larger things, on leaders. The Preserve, after failing to think through its bolting policies, learned fairly quickly to set up rap lines that did not go down routes. Betty is a popular route for beginners and has got to be one of the worst imaginable places to have a rap route.
There has been an anchor around this tree for the last 20+ years so there is nothing new here. People use this rappel regularly and are used to it.
None of this makes it any less poorly conceived and undesirable.
Does that make it a bad thing? If there were not a cable here, there would be a tangled mess of webbing that looks like shit and very few bother to clean up.
I think the cable is actually an attractive nuisance. It encourages people to rappel back down the route, people who might have at least thought clearly for a moment about it if there had been webbing.
Cables give the illusion of safety, but we know nothing of the competence of the installer and can be fairly certain that once installed, no one is looking out for the integrity of the system or thinking about the kind of periodic replacement that such installations require. Indeed, who knows how to judge the integrity of cables?
Climbers understand how to inspect webbing, and if it gets messy, all it takes is a knife to clean it up.
I personally like having it there and am grateful to the person who replaced the sketchy setup that was looking a little aged.
I personally thought about cutting it down, but found that I neither had nor wanted to purchase the necessary tools. I was concerned that less expensive ad hoc methods might fail, leaving a weakened installation, which would surely be the absolute worst possible outcome.
There should not be a cable rap anchor directly above an extremely busy beginner's route.