Perhaps pot heads don’t feel the need or desire for conviviality that those having a drink or two do? This also is self-evident.
I think you’re right. Potheads often like to just space out and drift away from reality. Alcohol drinkers lose inhibition and for some it allows them to come out of their shell. Others let the devil out of themselves after just a couple of drinks. Each drug has its downside and tradeoffs. I think we fool ourselves when we uncritically praise pot like some posters or act like we have to find no fault with booze.