Let's step back a second and use a very clear observation. This is like saying to someone overweight - why don't you stop eating crappy food. Look at the mis-information, man. Additionally, social "norms" force a lot of cultural influence to do so. This falls in line that America is a "drinking" society. Go watch Ken Burn's Prohibition just a fact of record. I haven't even touched on the addiction aspects, because I think its self-explanatory on how it plays out on people - no matter if its eating, smoking, drinking, etc.
No, this is like replying to someone's statement "I was forced to eat unhealthy foods." by pointing out that they are shifting the responsibility of their actions onto their circumstances and surroundings. Those may have an influence on you, but the best way to see change in your life is to accept responsibility for your actions and bring them in line with your goals.
