[room271]

Mobile phones (via apps) are a lot more monetisable. Part of the decision may have been motivated by this (i.e. push mobile users towards the apps by limiting the responsiveness of the main website).

I'm not saying I agree with this (and I don't have any real evidence that this guided the decision) but it is a possibility.

[stevesunderland]

this is really the only valid argument for a non-responsive design. kudos to you and your sensibility.