I guess I'm nuts, then, because I DO pay extra if a resort has a nicer pool! My son likes to spend time there, and my expectation is that I will have someplace to sit and watch him. If I can't find an empty seat, then discover that it's because there are a bunch of people "pool hopping", I get a little upset. I don't consider that elitist, just getting my money's worth!
Most of the resorts aren't that busy at lunchtime, or even dinnertime (unless they have a special show) so it doesn't matter if "outsiders" come in...they aren't interfering with my use of the amenities. A lot of the deluxe resorts have character breakfasts...which are an extra price, even for guests who are staying there. As I've stated (for the 3rd time, already) I have no objection to guests from other resorts using "my" pool (if I happen to be staying, and paying extra, for one with a cool pool) as long as it doesn't prevent me from enjoying the amenities that are included in my room rate!
And yes, I know there are other places in the world where purchasing a beer in the bar gets you unlimited use of all the resort facilities...but most places in the US require that you be a registered guest. The hotel/motel restaurants, lobbies, and bars are considered "public" areas...the rooms, pools, and exercise facities generally are not. I HAVE stayed at hotels/motels that sell memberships to local people (such as the beach club I belong to) but they are not open to non-guests or non-members. I don't know about a lot of other beachfront areas, but most of them around here would consider you a tresspasser if you used their pool without being a guest/member.
And there was a time when any WDW resort guest could use all of the amenities at any other WDW hotel...but that was when there were fewer guests, and all (except Ft.Wilderness) hotels were "deluxe" hotels (and cost the same)