There may have been a stealthy power move going on back then to kill off the GPU by denying them anywhere to plug in. When Intel successfully killed off 3rd party chipset makers nvidia was clearly quite worried and successfully sued Intel with the result they were required to keep PCIe expansion available on their chipsets with enough bandwidth for GPUs. (This agreement expired some years ago, I think it was only for a decade)

This wasn't an unreasonable worry for nvidia to have. They'd just lost preferred chipset status on AMD platforms when AMD purchased ATi. Intel had released some lower end platforms with only 1x pcie connections (nvidia had responded with nvidia Ion which could work over such a tiny link) and AMD was talking big about their APUs.

It was a reasonable fear back then that Intel and AMD, with a tightened grip on their platforms and their own integrated solutions competing in the same space, might choose to just cut off nvidia's air supply by flooding the market with chipsets that didn't have the connectivity Nvidias cards needed.