Rather than make broad claims like "pretty much all"... if you took a little time you might quickly realize which kind of drivers work and which don't.
I'll give you a hint... plug in a USB webcam (even one from Microsoft) into a Windows RT device and see what happens.
Allow me to save you some time: No driver will be found and you won't be able to use it.
Does this mean we have a conspiracy not only to kill off Ethernet but also external webcams?
That's not comparable because the Surface has a webcam built-in already.
You make it sound like a technical decision. But it's political:
Apparently these drivers mentioned in the linked post work without any problems.
OK, let's say the reason for all this just for more simple: To sell more Surface Pro devices. Still lame for Microsoft to take down third party Ethernet drivers.
Quotes from link:
A company named Pluggable makes several USB to Ethernet adapters 10/100 & 10/100/1000.
This company has posted on their website that they were requested (demanded) by Microsoft to remove the drivers for their products that are compatible with the Surface RT.
Great guide tonyman.
I received my adapter from plugable today and installed the "banned" drivers on my RT. Finally
I can use it in the office. Really strange policy by MS to limit working functionality for their users
If someone bought a Surface, it's their device and they can install whatever they may wish. I know, not very cool to say this in today's prison IT.