The way I read this, TIM FREAKIN' PATERSON, the man who wrote the most hated "operating system" in history, put an algorithm with a nasty performance bug into the standard library of VB, and conveniently forgot to document that this function is no good for large and/or repetitive inputs. Confronted with his blunder, he not only doesn't correct his blunder, but instead condescendingly proclaims that those inferior VB coders would never need long strings, just like 640kb ought to be enough for everybody, and if they did anyway, they'd surely use a library written for the purpose by a real programmer.
The arrogant prick should have listened to the new grad.