Why not? Plenty of people own parks and gardens that are open to the public. Art in galleries is all owned by someone but many are free for public viewing. Everyone getting to enjoy the thing while the creator still gets paid sounds like an awesome future to me.
Because “ownership” is the right to exclusivity.
> Plenty of people own parks and gardens that are open to the public
You can choose not exercise the right to exclusivity (or to do so selectively), but if you don't have it, you don't own anything.
> Everyone getting to enjoy the thing while the creator still gets paid sounds like an awesome future to me.
Sure, patronage of public art can be great, but it's not ownership (except maybe “ownership” of an exclusive right to receive some defined form of credit for the patronage.)
Their is no ownership without exclusivity.
(And NFTs are exclusive; they just happen to currently mostly be used as pointers to non-exclusive items with no other meaning, but there is nothing inherent in the technology restricting them to that use.)