It doesn't have to be anticompetitive conspiracy, milking current technologies for all they've got make sense in a lot of ways. Making your previous generation profitable by delaying your next generation a little means your business can last in the long term. Releasing things ASAP in every instance means in many circumstances competing with yourself.

This is a cost of capitalism but it comes with the benefits of a self-sustaining system and more predictable futures. If politicians were funding processors, you'd bet they wouldn't want to spend the resources to double processor parameters every 18 months.