> academia which is rife with money sloshing around

In the academia that contains money sloshing around, the only grad students teaching are the ones who want to.

In the academia that doesn't contain money sloshing around, it's a different story.

But the truth is, no one in academia is making bank from academia directly -- not the grad students, certainly, but also not the adjuncts, or even the professors. You have to look higher up the chain (or, I guess, laterally?) for that. (Yes, there's the caveat that some faculty make good use of their prestigious affiliations or professional connections to increase income from outside of academia.)