I think you’re reading too much into this. If someone is homeless, parking in a high-traffic national park that is patrolled by rangers and has limits on how long you can stay isn’t going to happen.
An annual park pass isn’t that expensive. People who live in an RV would spend far, far more driving to and from the park for various things they need (gas, supplies) than they’d save on the park pass.
Regardless, having a pass doesn’t eliminate the rules regarding duration of stay. You can’t live in a national park even if you have a pass. If you try to do it in an RV, you’d get noticed and cited.
An annual park pass isn’t that expensive. People who live in an RV would spend far, far more driving to and from the park for various things they need (gas, supplies) than they’d save on the park pass.
Regardless, having a pass doesn’t eliminate the rules regarding duration of stay. You can’t live in a national park even if you have a pass. If you try to do it in an RV, you’d get noticed and cited.