I don't think that the fact that they serve alcohol in other areas of WDW is really relevant. We can only guess why Walt was concerned about serving it in Disneyland since he was known to drink somewhat himself. My guess would be not because he thought alcohol was a terrible thing, but that since it was a family park, the influence that it might have on the kids was his concern. There was a time when we worried about stuff like that. We cared what kind of things that we were exposing our kids too. Now we use any language we feel like with no concern for who hears it. We feel that getting a buzz on in front of our kids is OK. Nothing is done to make the world a little less stressful for them. Walt smoked like a chimney, but do you ever see him smoking on TV, or on any of the promo's he did? There are some occasional candid shots that show him smoking but it was rare. Was he against smoking...obviously not, but he did care about what example he was giving to others. Why is that not responsible behavior and why is it no longer something that we should be mindful of.
Our children learn proper behavior by the example that their parents display. Why is it that, as a society we cannot go a few hours without alcohol especially as I am sure everyone that says they can't, also say that they don't have any addiction to it. Why is it that values such as self respect and responsible public behavior is no longer the trend. OK, it's a changing society, but is it changing for the better? I think we have to ask ourselves that question.
Now we will have drinking in MK. End of the world, probably not, but you know as well as I do that amongst all the guests that go to WDW there will be a notable percentage of people who cannot stop at one, who are in every sense of the word...alcoholics. They will be there and they will make their presence known. You can give matches to a kid and they won't necessarily burn the place down, but if they don't have any matches they definitely will not.