At Disney hotels they are indeed the nightly room rate during peak booking seasons and yes, people pay for them.

They also, from my calculations, include additional charges like extra persons, roll away beds, etc. Pretty much the max they could possibly charge you for physically occupying the space.

Having your occupancy hover around 90% allows you to pull such extreme rates - and the majority of other hotels in the world cannot afford to charge their max nightly rate short of special events.