Perhaps all that infrastructure that was put in for the soccerball does have some legacy use (Expo, winter sports tournaments etc) and some of the hotels just don't want/need to host ultra cheap one nighters who may also tend to eat when they get back to the airport. Things may change again once the winter is over.

But c.GBP 22 for the standard 4* and GBP 38 for the premium 5* hotels is still excellent value, and arguably a much better room than the short time offer in AS.