Both are good medicines when used as intended, just as both are bad when abused. If you don’t believe me start abusing aspirin and enjoy the ulcers they will give you eventually.
Point taken. One could always go back to the "original" white willow bark that Bayer methylized into aspirin, though there are alternatives available these days.
I think the only way heroin could be considered a "good medicine" would be as a palliative in hospice care, certainly not as the cough suppressant it was invented to be. FWIW, I say that as a caregiver for someone, with MS and degenerative back issues, who has been in pain management for over a decade now.