Earlier quoted context omitted.
Because them some people think it's still ok to go with the broken code That's cultural differences 101 As a simple example: in Canada one might say "please do not feed the animals" in a Zoo. In some other places, for the message to have the same effect it must be as such: "It is expressly forbidden to feed the animals! Those being caught doing so will be expelled from the zoo!"
Wait. "Broken" code?
"And yes, you still could have overflow issues if the whole "hlen + xyz" expression overflows, but quite frankly, the "overflow_usub()" code had that too"