Then how will they ever get off the benzo? If they're clearly still wanting it for the wrong reasons, I see, but from personal experience, in private practice, when I explained to most patients that benzos are bad for long-term treatment, they wanted off of it and were fully cooperative with my efforts to wean them off.
Now, unfortunately, that was not the case in other practice settings, but in PP it was.
You could get prior medical records and in some states you can get a hold of reports showing every single controlled substance they've gotten from pharmacies in a matter of moments.
I see your point about weaning someone off of benzo may in fact be giving them one they shouldn't have, and may have misinterpreted your meaning, but it appears you have a "if they're on a benzo, I won't see them" mentality.
Patients on large doses of benzos, I tell them if they want to continue seeing me, I will have to get them off of it, the question then becomes how much time will I give them. This depends on the specific patient but in general I usually have them completely off in 1-4 months in an outpatient setting. I have given some other patients much longer than that but these were exceptions to the rule and on the order of less than 10% of my patients on chronic benzo usage.