Most hotels would have a good case to charge for parking if we had things like land value taxes.

It still takes up space, that you either have to rent/buy extra as hotel or can't use for more sensible stuff. If anything, if parking is free, everybody is paying the fee even if you don't use parking.

Yeah, charging for hotel parking in NYC, DC, or a dense part of Seattle is an entirely different beast from charging for it in Montana or the outskirts of a national park. The question comes down to if it's reasonable for you to have gotten there without a car and if it's reasonable for you to get around where you're going without one. For places where not having a car with you is unreasonable a parking fee feels like a hidden fee for everyone, where for somewhere you probably flew into and can take public transit around it's charging for an extra amenity.

Charging for limited stuff makes sense, otherwise the hotel would need as many parking spots as it has beds

Sadly people seem to struggle with thinking in terms that aren't black and white. A position like yours seems to blow their mind.

While I do agree that cars take up far too much space, charging a guest for parking is a bit of a dick move under most circumstances.

It's really not. Most of the time this is because the local jurisdiction taxes parking in some way, and as is always the case in the US, the local business isn't going to absorb those fees.