Every cocktail is pulled out of a soda gun
Nobody wants to drink a fizzy, pre-made Old Fashioned with a slight hint of Diet Dr Pepper.
They use a bunch of gross old fruit as garnish
Sure, it took you a really long time to slice a couple lemons into wedges then open that jar of maraschino cherries. But maybe it's time to toss them out and let the fruit flies have 'em. I mean, they're already all over the container anyway.
They scoop ice with the glass… or their hands
The latter is wildly unsanitary, the former could result in shards of broken and chipped glass hiding invisibly in an ice tray, which could lead to some internal bleeding, which is also wildly unsanitary.
They keep pouring drinks out of pitchers
Sure, punches are super-hot right now. A pitcher full of Long Islands that's been sitting there for a week? No. Just no.