Depends where you live. Many clubs display prohibitive/punitive fares on purpose, by the owners' own admission - not everyone is a rational market agent.
In many clubs there are also areas (usually smoking ones, but also backrooms, lounge areas, and so on) where the sound is muted and conversations (and other things) easily take place.
No club is trying to discourage patrons to have drinks.
Also, some people like conversation. You can't have that at a nightclub