Your assumption is mostly valid about the quality of cable tv provided at most RV parks/resorts, what you'll really get is degraded video quality and generic channel selection. In Phoenix area OTA reception is excellent and can readily fill your major network needs if that is your only requirement. Wifi is a joke at most RV parks, primarily limited to checking emails and minor surfing.
No doubt it's easy to see that many RVers want more and thus use satellite tv to provide all the same channels they have at home, after all that's what RVing is about. If you have sat tv at home grab a receiver and decide to go with a manually pointed set-up or automated pointing device. For sat tv just for RV use a few months a year, Dish Network is the way to go.