Booze is a wonderful muse for musicians. It's the only thing besides love that gets the creative juices flowing and spilling out into the studio. That doesn't necessarily mean, however, that liquor is reliable for producing great songs.
Because there are plenty of really, really bad songs about getting smashed - UB40's pseudo-raggae ode "Red, Red Wine" immediately springs to mind - and plenty more terrible songs that have nothing to do with drinking at all, except that they were dreamed up and maybe even recorded during a drunken stupor.
Also, we should clarify that there's a difference between "drinking songs" and songs about getting drunk. And they don't always overlap.
Drinking songs are a dime a dozen. Really, once you get past that fourth beer or third shot of whiskey, every song becomes a drinking song. So it's not that impressive for a band to have a few songs in their discography that become synonymous with a night out on the town.
But it takes a special talent to actually write a really great song about getting drunk that isn't A) super depressing and B) mostly just listing all of the labels on the bottles you see behind the bar.