a) Life without walls? where the hell are you going to put your "Windows"
b) Stop talking about price, you get what you pay for is one of the worlds most popular catch phrases – so essentially they are saying "We are cheap, we are rubbish!, mac is expensive, they are good"
c) They arent advertising Windows! People watching those ads, see the computer, and the store! not the computer. They may as well say "Buy this box that doesnt do much, we arent going to show you what it can do!"

I hope ive made my point