I would have liked an answer to the "why" in your title.

I'm going to disagree with your point that it's good for us to tie one on now and then. I think getting drunk is never a good thing to do. That doesn't mean you can't enjoy a glass or two of wine or a cocktail at dinner or in other social situations.

Many of the biggest mistakes people make in their lives happen because of being intoxicated.

If you are home alone or with a partner drinking to get drunk, why? There are healthier ways to manage stress and deal with emotions and/or problems.