My comment was a suggestion/question, not a one size fits all prescription. There is definitely some nuance you are looking past.

Going cold turkey is a serious approach and for some addictions like smoking the most statistically successful approach to quitting.

S/he is telling addicts to tell themselves to stop.

The person is claiming to have obsessive compulsive disorder, which can operate a bit different from regular addiction.

That's because this "cannot do" definition of an addict is incorrect/harmful. This is the disease theory of addiction (addicts can't help themselves) and has been proven wrong/harmful in recent psychology.

Sometimes addicts don't actually want to stop. Instead, they just want to slow down or control the thing they are addicted to