Except that references still can be bad: invalidated later on by an object deletion, no matter how many rules were enforced to assign the reference to begin wit

Except that references still can be bad: invalidated later on by an object deletion, no matter how many rules were enforced to assign the reference to begin with. And in an almost-worse sense, "sometimes" references can prevent this and sometimes not. Just not good enough, while syntactically making it harder to tell that references are being used in function calls and such.