The article was good, without the "Morons" at the end directed at Hangzhou Sage chemical company. It didn't need that, and it reeks a little of racism to pretend they're morons for working with FOOF, considering how much he lauded respect on Streng for doing so. The article already had good comic effect without needing to do it at someone else's expense whether it was racist or just cruel and dismissive.
The insult was for abusing that catalogue and falsely claiming they could commercially produce and ship something that they could not, and I think it was fairly deserved. I don't really see any sort of racial dogwhistles or subtext here, this reads like a small snipe over questionable business practices.
I think he was making fun of them for the fake listing. Offering 1kg of FOOF in a chemical database is like offering a nuclear warhead with free shipping on Amazon. Both are so ridiculously dangerous that they will surely not be publicly accessible.
