I like the Netgear approach of installing the router as a wireless setup. They recommend that you do it this way, presumably to bypass any network issues on the old ethernet side, such as the subsystem being disabled at BIOS level, or of a non computing type person being freaked out by the concept of having to identify anything more complex that a mains electrical plug. You do have the option of going the other way around should you wish though and I agree that it is unusual, at least compared to the other routers that I have installed.
Conan