Irrespective of whatever you think it should or should not be, it is owned by the council, like the roads (which is why you or I don't fix them or build them, they do). As such they can dictate how it is used, like they do the roads. Yes they provide them as a public facility, as they do many things, but all come with caveats.
By your rational, the council can at anytime decide that PPR is now a thing to use their roads, and they are removing the street lights and banning driving between sunset and sunrise.
I’d like to say this is all the thin end of the wedge, but we are well past the thin end. Is just like to know how far the wedge extends at this point.