Responding to this comment from the original thread…
I think I don’t understand what you mean by “academic potential” and how that is similar or different from “earning potential”. You can get a PhD in just about anything.
And it turns out the government doesn’t pay to employ many of those biology grads either.
What about history, philosophy, classics? Those are all fields with a long and illustrious legacy. There aren’t great jobs for grads in those specific fields and the government doesn’t really fund those fields at all.