He's not "blaming" anything on immigrants; he's saying the simplistic statistic presented is confounded, and is unlikely to show the direct correlation between funding and student outcomes that it purports to show.

You're required to be charitable here; it's in the site guidelines. Yours is not just an uncharitable interpretation, but a deliberately inflammatory one.

No. I am not going to be charitable to an obvious attack on immigrants.

It wasn't "an obvious attack on immigrants", as anyone who's read many of rayiner's HN comments would know. Please follow the site guidelines.