Because why not. I just bought a new laptop (clevo p150sm [I7 4700QM;16GB;840ProSSD;GTX780M]) and there was no windows on it. My university has windows deals for windows 8. And I think windows 8 is better then windows 7. Why do you hate it? Because of the metro screen and because there is no start menu? I didn't use the start menu in windows 7. Just click the windows key and type the first 2 letters of the game/ program you want and it launches with enter. It works the same on 7 and 8.
My girlfriend thought the same as you. But after I chose a windows 8 laptop for her. (she thought it was windows 7). She just needed to work with it. And after 2 weeks, she couldn't work without it.
If you really want a start menu on win8. Try this then: http://www.stardock.com/products/start8/