"Why would you hire FOO programmers that felt they couldn't learn BAR?"
Did they really feel they couldn't learn it or were there factors in them not wanting to learn it? What if I was worried about future job prospects after a few years of BAR development?
Personally, I'm pretty elitist when it comes to programming. I think about nine out of ten people who are being paid to write software today should be shown the door.
Most of the industry is a scam (however inadvertent.)
Now, in 2017, most folks software needs could be met by picking and configuring canned components from a library. There really isn't a lot of requirement for real programming.
But we just keep going. Another JS framework. Another chat app.
But I'm starting to rant now. I'm close the window and back away slowly. ;-)