These aren't "other product lines" though. They are RTX and Spark SOC products that do support Linux as a first-class citizen with all of their hardware. The RTX Spark is the outlier, and the breakage is not on the GPU product, but the SOC devicetree drivers. This is only a problem because Nvidia avoided standard Windows power management a-la ACPI/UEFI, and has to port the remainder to Linux by hand. Non-laptop products like the DGX Spark support this via UEFI natively.

There are OEMs that refuse this responsibility. If that's the vindication you wanted, there you go. This specific issue is not a catastrophic oversight though.