If I say "You have a big nose, it makes you ugly" as the first line in my email, it may well be a "statement of fact" and yet still be a personal attack. Your implication that a statement of fact cannot be a personal attack is untrue.

Whether the OP has or has not written Posix utilities in rust is of no relevance to the actual argument whatsoever, it is just a way to have a dig at the OP.