I didn't like the attitude in the original post, and I can understand why there is a little spice in System76's reply. Recommending a competing laptop brand over an issue as trivial as an alternative BIOS update mechanism that doesn't match Microsoft's compliance requirements seems like seriously sour grapes.
It seems they expect System76 to invent an in-house firmware update system that does not use the official mechanism supplied by their chipset's support package, and somehow this is automatically a better outcome than what existed already.
Maintainer should be reminded that toiling for free (presumably) on an important subsystem grants no special rights or entitlements, and lashing out at a vendor because they didn't toe an ideal line looks very immature
edit: sadly maintainer isn't even working for free, they're a Red Hat employee