I mean it's to be expected only in the way that it's been going on since the year dot, not that it's something I'm happy with.

My opinion, and as I understand it, is that the hotels are selling the brand to the customer, rather than the size of the room; it's more a case of 'I'm staying at the Savoy' for example.
The hotels in that category know that they will sell their rooms based on that premise, whereas people staying on a tighter budget, or on business, will only be interested in a good price per sq metre, and the hotels in that category also realise that premise.