I think everyone in this chain should admit that hiring the kinds of developers you can 'throw x language book at' and a week later you have a competent x lang developer is an incredibly expensive and time consuming processthat most companies will never be able to afford.
Even if you can, you then have to solve the issue of keeping a department stocked full of senior devs happy when you have limited promotion/perk/raise options and so churn will likely be relatively high even in a healthy environment.
It's a nice fantasy view of the market as an ideal world simulation but does not reflect the reality of hiring software engineers.
You can't buy a book, keep it on a shelf, lend it to new hires, and afford to have an employee take a week out of being productive to learn something? Or you can't afford salaries for a company of people who have more than 5 years of development experience?
