oh jesus, if there was a poll here that was voted on by everyone on TPU you would most likely fine that 50% of people go Intel and 50% go AMD. That same logic can be said for GPUs as well. Physics is a gimmich for Nvidia to sell more cards. The only Game coming out this year that I know of that uses PhysX is Borderlands 2 and even then thats only 3 of its features. Dynamic liquid, clothing, and particles. I can tell you have not been around computers and informed on what is going on technology wise for very long.
AMD/ATI cards are actually VERY high quality, just as good as Nvidia. Nvidias Geforce Fermi GTX400 series were pretty shitty in regards to quality. AMD is very much wanted in this industry. They provide a much needed competition against Nvidia. Have you ever heard of a monoply? If AMD/ATI were not making Video cards nvidia would be the only one making them, and the pricing would be through the roof.