The point is that they don't need to be networkers, because they will be networkees. i.e. other people will notice how good they are, and actively try to get them into appropriate jobs.

I think this is largely true, though it takes a while for reputation to spread. There are some brilliant young developers who haven't yet been noticed by anybody in a position to hire them -- but they won't stay in that situation more than a couple of years.

The exception is somebody who is excellent, but stuck inside one company and not producing any publicly-available code. If she isn't actively promoting herself, it's possible nobody will ever notice her talent.