Aunty,
Just because some people will find a way to do something anyways, doesn't mean we should just allow them or make it easy for them. At least we could make it harder. Besides, if it is illegal, I would suspect more of them would do it at home, making them less likely to drive. The guy I stopped from driving home last year was pass out drunk. He was also a 50+ business man, dressed nicely, driving a very nice car. I doubt that if he couldn't get alcohol on the way home he would pull over and get some crack or heroin. The cops told me he had 5 convictions and that they had 20+ calls to 911 in the last hour on him. I really felt bad for him as he kept saying, "I got a problem. Let me drive home and I will be ok tommorrow." Unfortunately he was too drunk to do it or even remember the way.
I also had a sweet old couple late 70's stop by my office one day. They just wanted to ask me a business question. The man apologized, and admitted, "i might forget about this talk because I had a little too much to drink at lunch. A little, you could smell them from 20 ft. After our quick conversation he walked out and got into a brand new cadellac and drove off. Had another guy in his 60's invite me over to his house to see if we could do business. As we walked around his house, he pointed out a boarded up window and laughed, "I got a little drunk last month and shoot out the windows. Went to jail for that one."
Had another guy on a job site explain to me how he just got out of jail for killing someone while drunk. He was actually mad about it. "it's not like I went out drinking with the intent to kill someone, it was an accident."
All of these people, but the last one, were older, established middle to higher income people. I really am not comfortable with them being able to walk into a store and buy alcohol and see no problem if they were forced to either take a break or be stopped from ever having alcohol. If you can't drink responsible, you shouldn't be drinking, period.