Making things opt-in means that it will happen less often, making them opt-out that they will happen more often. In this case, on the one hand you have destruct

Making things opt-in means that it will happen less often, making them opt-out that they will happen more often. In this case, on the one hand you have destructors that don't run when they should, and on the other you have destructors running at a more granular level than you'd want sometimes. I know which human failure mode I prefer.