Biggest point here. You can't flunk out 90% of your applications and complain you have a shortage of qualified staff. You have people begging to work for you, how about you hire a few of them and teach them anything that's missing. Oh the horror, the employees aren't replaceable meat cogs in some giant machine.

That is illogical. If a million plumbers and no programmers applied to be programmers, would Google be wrong to not hire them? We are talking about skilled jobs in a specific trade.

Why are you interviewing the plumbers? If a million plumber and no programmers applied, you would immediately reject every resume and not interview anyone.

Note that this assumes none of the plumbers have been working on teaching themselves software development in order to make a career change and thus do not have non-work evidence of competence.