[VikingCoder]

You're a manager and realize (reluctantly) that you need to hire another programmer...

What's the strongest indication of success? If someone already on your team recommends them.

So, my theory is, programmers at companies know other generalists, and recommend them (successfully) for generalist positions.

And the reason you see job postings like you do (technology X and technology Y), is because the people who work at that company don't already know someone who knows those technologies, and is looking for a job.