Is the following what you're referring to? If so, he's specifically referring to training programs for existing googlers. Not educational training for full-time students, and someone looking to make a career switch. The latter clearly has a much bigger impact than the former.
Regarding your larger point, I agree that we need more support for the lower middle class, but that's no reason to abandon training programs that provide better job opportunities to those who need it. On the margin, training a thousand janitors into productive web developers, would be a net positive for the economy and society as a whole.
https://www.linkedin.com/pulse/i-have-just-finished-reading-...
"Did you know that within 1 hour of training an employee, they have forgotten 50% of what they were taught. Within 24 hours they have forgotten 70%, and within a week they have forgotten 90%.
There is mostly because people truly learn from constant repetitive actions, yet companies cannot afford to have people learning 5 days a week instead of working 5 days a week - which makes 90% of training and development programmes a waste of money. Money which Google invest in recruiting instead.
Laszlo Bock says that because we learn on the job, the very best people not only have learnt more than you can teach them already, but they seek learning themselves in everything they do and naturally grow without you needing to spend a fortune on training."