I don't like them. They are semi-permanent, violating the traditional idea that anyone can place anchors and anyone can remove them. This means that someone makes a decision for all users and the Preserve itself about how the land will be used.
Although the cables probably last for a very long time, I don't know any way of forming an opinion about how reliable they are, and the ones encased in garden hose hide most of the cable away from evaluating eyes.
When they are installed someplace like the top of Betty, where there really shouldn't be a funnel channeling everyone back down that route, it becomes clear that the judgement of the installers can be poor; nonetheless the difficulty of removing the cable forces everyone else to live with it.
The one thing I doubt is that the cable is any more damaging to the tree than slings are. The real culprit is soil compaction, but to the extent that the cable draws more rappellers to the location, it might still be responsible for hastening the demise of the tree.