That assumes that the only purpose of college is job skills, a recent phenomenon. College is to teach people about the world and how to reason - the ability that separates humans from beasts, civilization from barbarism, the Enlightenment from the Medieval, fact from fiction (a skill desperately needed these days) - by studying the great reason and 'reasoners' of the world, current and past, in all different fields from science to literature to math to political science. If you think you can reason as well without that, with only coding school, I think you're kidding yourself.

Also, the lifetime wages of college degree holders shows demand is pretty high for them.

Finally, when people say college isn't necessary, they meant 'not necessary for lower class kids'. I assure you that every Senator who proposes cutting education funding is sending their own kids to college, as is almost everyone reading this on HN.