I don't really have an issue with this. I know it bothers some people but I hate the possibility of limitations due to maintaining backwards compatibility. I would much rather have as much new stuff as possible with each release than have the ability to use an old motherboard.

I know that those reasons may not be why they do it, they sell chipsets as well as processors, but I am going to buy a new motherboard anyways. I have no use for a processor with no motherboard to put it in so I always get a new one with the new processor so that I can do something with the processor I am replacing.