Until people realise that this is a rational and sensical decision there won't be any solutions for these problems and these cases.
The US drug "treatment" / "rehab" industry is notoriously awful and is dominated by pseudo-religious ideologues obsessed with abstinence (to the point that "cult" is often an accurate, non-hyperbolic term) and whose practices are not based on any medical evidence of what reduces deaths. It's a fucked up industry that loves to use degradation, isolation, and humiliation on its "patients", loves to make people withdraw suddenly from their drug use and force them to endure the withdrawal symptoms, and isn't even particularly good at helping people not die from heroin/opioid use.
Given the current state of the rehab industry, and given how ineffective the "treatments" it offers are, it can alas be a rational decision to avoid it.