Not to mention embedded software is often half the pay of a startup and defense software often isn't work from home. Forget asking what languages they can hire for. They are relying on the work being interesting to compensate for dramatically less pay and substantially less pleasant working conditions. Factor in some portion of the workforce has ethical concerns working in the sector and you can see they will get three sorts of employees. Those who couldn't get a job elsewhere, those who want something cool on their resume, and those who love the domain. And they will lose the middle category right around the time they become productive members of the team because it was always just a stepping stone.