So hotels have gone to greater lengths than airlines in trying to get customers to book direct. Generally when you book on Expedia you still earn frequent flyer miles for your flights, and are eligible for elite status accrual and elite benefits. (Although it may not always be as clear what restrictions apply to the fares you’re buying.)
Hotels on the other hand have imposed restrictions on points-earning, elite status earning and elite status benefits on these reservations. Now hotels are winning the battle over how much commission to pay, and what rates to even make available to online booking sites.