I don't think this comment draws the distinction between people who came here without long-term plans, and people who came here and left because they felt they would not be welcome long-term.
Why? If I (an American) studied in the UK, did I somehow betray the British by returning to the U.S. after? I paid tuition, I contributed to the economy while there, I helped bridge cultural gaps.
Your example is also peculiar because of the relationship between the US and UK, any advantages you gained in the UK might help the US instead of the UK but it will not harm the UK's security or industry because of friendly relations, legal cooperations and extradition treaties. China and countries not friendly to the US training people in the US who will go back and develop industry and technological advantage all on US taxpayer's dime isn't the same thing. Even when you pay tuition, a public uni or a gov sponsored grant is subsidizing much of the cost you would otherwise been expected to pay.
But why do you believe that? You're asking for the article to prove that isn't the case, and I'm asking in all earnestness, what is the argument that it would be the case?
I mean, student visas don't even allow most of them to stay if they wanted to, you can look up student visa stats for China to find proof for my point.