IMO not every coder is sloppy with use-after-free. Not everyone is slopy with incorrect mutability. [...] Not everyone is sloppy with $THING[N]. But it's hard to consistently not be sloppy in any one of them, and N are so many that almost everyone is sloppy with at least one of them, most of the time.

Each probablility of a mistake may be low on its own, but they compound with every avenue to make mistakes.