If it takes "10 years" to learn to program, and you hire a guy five years into his ten years, and the average duration of employment is two years, and all of these clauses are "common knowledge" regardless of whether they are actually true, you can see the problem.

Training is a real long-haul investment, and in an at-will environment and culture even strictly considering the employer's side in an environment where the employee can leave literally at any minute makes this a very risky move. Train people to some extent, sure, but like actually give them the equivalent of a college education "on the job"? Sounds like a fast way to bankruptcy to me.