Gin has changed in recent years, here at least - there's been a massive boom. Now it's for girls who want to look more sophisticated and have it instead of vodka and coke, who think having it in a goldfish bowl will make them "classier" and pretend they can taste the difference underneath the elderflower tonic they've drowned it in.
Guinness is also a drink that people will use to pretend they're connoisseurs and maintain that it has to be topped after specifically 142 seconds for the perfect pint.
But I think Odder hits the nail on the head; drinking what you like doesn't make you a gobshite, but talking about it as if that's what makes you interesting does.
"Claret is the liquor for boys, port for men; but he who aspires to be a hero, must drink brandy."
- Samuel Johnson