Keep in mind that a great many RV parks are NOT located where broadband internet in available. If a park can get decent DSL consider them lucky. It's not too too bad for a family of 4, but multiply that by 65+ RVers, with 2+ devices per site, and it caves in very quickly.
People want a park off the beaten path, remote, rustic, and away from road noise and the sounds of suburbia - and then they want all of the creature comforts that they enjoy at home. It's kind of hard for a park to provide those creature comforts when the infrastructure isn't there to provide them.
Many RVers don't like the park cable, the few channels available, or the poor picture quality - so they bring their own tailgater, walk out dish, roof top dish, or dome. If you don't like RV park internet then why not bring your own internet access to the park with you?