Is it a good old word or a bad one? Well it’s certainly an old word. The Online Etymology Dictionary says it goes back to around 1290:
piss (v.) … c.1290, from O.Fr. pissier “urinate” (12c.), from V.L. *pissiare, of imitative origin. As a pure intensifier (cf. piss-poor, piss-ugly, etc.) it dates from World War II. Pissed off “angry, fed up” is 1946, U.S. slang. To piss off “go away” is attested from 1958, chiefly British. Piss and vinegar first attested 1942. Piss-prophet “one who diagnosed diseases by inspection of urine” is attested from 1625. Piss proud “erect upon awakening” is attested from 1796.
It pops up fairly often on beer and wine labels. Above is Horse Piss Beer, made in Louisville, Kentucky. Another beer along these lines is Piss Brand Beer, made in Australia. And then there is Pisse Vieille wine, from Beaujolais. Wiki explains the name thusly:
The Brouilly cru also contains the famous Pisse Vieille vineyard (roughly translated as “piss old woman!”) which received it name from a local legend of a devout Catholic woman who misheard the local priest’s absolution to “Allez! Et ne péchez plus.” (Go! And sin no more.) as “Allez! Et ne pissez plus.” (Go! And piss no more). The vineyard name is the admonishment that her husband gave to her upon learning of the priest’s words.