For the DGX Spark and OEM variants a big issue is that the ConnectX-7 is just not designed to have low power idle but instead to be efficient when loaded.

NVIDIA already lowered power draw at idle by 18W with a currently out of tree driver leveraging PCIe hotplug for the NIC earlier this year.

I think that quite a bit more people bought those to use them without the ConnectX than what NVIDIA expected.