stifle

It's the same most everywhere else (with a very few hotels offering premium rewards cheaper than the standard rooms, e.g. Hilton Warsaw). Customer feedback was that people wanted the opportunity to redeem for higher categories of room, and Hilton brought that in.

I assume the redemption by category is built into the franchise specifications so hotels are obliged to conform to it. Hilton Corporate probably pays far more to the hotels for the premium room rewards because it has to buy them at somewhere close to the cash rate.