Most people purchase mainstream computers instead of high-end. And, during the last 3 months of last year (prior to Intel's release of I3/lower end I5), builders knew that LGA 775 (Intel's competition versus AMD in the low-end and mainstream markets) was a dead cpu socket.
Many OEM's (HP, Dell, etc.) even began offering more AMD cpus since they could more easily by hardware on a mass scale for them. (Fake example: HP Presario d7000... buy one AM3 socket motherboard and offer several cpus for it. With Intel, they would have to have 3 different motherboards... 1 LGA 775, 1 LGA 1156, and 1 for the i7 920.)
Whether 1 company's products are better in the low-end and mainstream markets didn't matter for this. Intel's LGA 775 end-of-life and change to LGA 1156 caused this. Now, if this continues, well... we will see.