As does World of Hyatt for hotels at which WOH points are used.

IIRC the reason for some hotel programs allowing stay/night credit for reward stays: Earlier, many hotel program members were not redeeming hotel points, instead using revenue rates, just so that they could (re)qualify for elite tiers. And these members were valuing the hotel programs less richly because their only practical value was in-property benefits.

An airline program, like SW, probably has a lot more occasional flyers who aspire to get enough points for a free flight, than those who want to (re)qualify for elite levels.