For unknown reasons the airline doesn’t have an agreement for discounted rates with any of the hotels or even the closest and thus most convenient hotels.
They do, till they run out of vouchers. Hotels sign up on a bid basis. As noted frequently on FT the DFW Hyatts have off the AA DFW list for years.
Hotels generally reported here are usually nothing to write home about, except maybe to say "don't stay here if you can avoid it".