I fully believe alcohol and smoking should be treated the same as sex - something you do in the comfort and privacy of your own home, where you aren't affecting other people. Once a week, after Match of the Day, with the lights off, if you must.
The problem is not "a glass of wine with a picnic in the park", it's the "6 cans of Stella for a fiver" several times a day crowd like those that used to hang around outside the Ritzy that many people, myself included, find intimidating.
I guess that, as I don't drink alcohol at all, I find it difficult to understand how having a glass of wine on a picnic can make it a more enjoyable experience.