Ooh yes, let's address next how US top universities are all profit machines incentivized to take as many foreigners as possible, driving up the tuition they can charge so US citizens can't afford to get degrees. Let's do talk about how if you get a part time job to be able to pay for college then they yank your financial aid.
While foreigners definitely are a cash cow, I think you'll find in STEM fields most foreign PhD students are not paying tuition, but are instead funded by US grants.
As for the cost of tuition, there are many, many reasons, and I suspect if you did a PCA, you'll find "raising tuition to milk foreigners" to be of minimal impact.
In my state, for example, a local university publicized their finances going back decades, and the increase in tuition has been mirrored by a drop in state support per student. Overall the university is not making more money per student than they were 30 years ago - the only thing that changed is the entity making the payments.
