I guess I don't see the point in debating this, as everyone's gonna do whatever they enjoy more. As far as chronic damage to the brain, organs and body of the user, opiates are the more benign substance. However, street heroin isn't regulated like alcohol and can contain substances that seriously fuck you up or even kill you, and opiates are somewhat more addictive physically than alcohol (physical addiction occurs sooner). Then again, alcohol withdrawals can actually KILL you, whereas opiate withdrawals just make you WISH you were dead. Both can cause death from overdose...SO...
I personally HATE alcohol to the point where I won't drink even a sip of anything alcoholic no matter the situation. It makes me have mood swings every time, and that's just not fun. Opiates don't make me nauseous, cranky, or out of control of my inhibitions and enhance my self-esteem, creativity, and enthusiasm for life when used responsibly. I've been out for 5 days now and, despite the mild irritability/fatigue/pain from withdrawals (I'm lucky not to ever feel pukey or truly "sick" and fully realize this), I'm not overtaken with desperation and misery. I have had a daily pod tea habit for like 2 months with the occasional one-day break, btw. Been doing them off and on since July without too much of a problem.
It all comes down to your drug of choice, I suppose.