I am already using adv locks to grant access to a resource manually (storage in my case). Its permanent access, and I am receiving a one time payment for this access. A key system would allow this process to be automated and I would not have to be present for someone to buy access to the storage system (that is for permanent keys). This isn’t an introduction of a new system but simply adding convenience to an existing one (it can be hard to line up play times with other players to meet and add to friends lists to add to a lock manually).
I could just as easily setup a system today with advanced locks to allow someone access to a walled off area as my storage units. It is different from granting beacon controls because it limits them to use just what is locked. In the case of a walled off resource, they can only break what is not beaconed, which prevents them from removing your walls if they had full access to your beacon.
I don’t recall what permission allowed you to use locked doors and not break things, but this lock system is an evolution of it, and a key system is an evolution of that. I can see why people would like the next step in convenience (as it feels like the ground work is laid for it).