if the linux kernel driver model wouldn't be so hostile to driver backward compatibility, it'd be trivial for soc provider to have a single device driver delivered with the soc and cut the certification costs by orders of magnitude.
this is something google could fix, btw, creating something like FUSE but for wireless chipset integration and keeping that backward compatible.
Manufacturers can get their drivers merged into the mainline kernel and they won't have a driver backward compatibility issue to worry about.
They choose not to for business reasons (market segmentation/artificial hardware limits via drivers) or because they are being cheap. And because much of the market doesn't know enough to care, it mostly works for them.
In the long run I think it limits the IoT ecosystem from progressing and it's a practice which must stop. If your hardware is not fully supported by the mainline kernel, it may as well not exist.
The argument isn't bad per se, it's just that reality disagrees.