I don't know about anyone else, but I have a TV that barely fits on my entertainment set. My Xbox 360 HAS to stand vertically to fit on the set or I can't use it. I don't have the space or the cord length to have it positioned to Microsoft's preferred orientation.
But, then again, Microsoft's latest business model appears to be "alienate everyone who does not live in a house with a fifteen by fifteen foot living room and perfect internet connection in every room", because NO ONE who is interested in playing their console lives in an apartment, or dormitory, or trailer, or mobile home, or townhouse, or condo where space is limited and internet connections are wonky. Nope. Microsoft doesn't serve that minority of gamers because, according to their research, they don't exist.