It made no sense. They were making the assumption that teams could turn up Thursday and setup Friday, but that would mean they would also have to kill all the support races on Friday too. Can't have forklifts in the pit lane while GP2 and GP3 are qualifying!
I don't get the tyre blanket idea either. Yeah sure they wouldn't make much difference if they weren't there, but I can't see how not running a few heated blankets for a few hours can be seen as a way to reduce any significant cost? Unless there is some massive nuclear reactor heating the tyres through diamond cables somewhere that I've missed, I don't see how it's a cost saving?