The problem is that this familiarity has created a vicious cycle, where the bartenders are taught to make the basic drinks, so people only order the basic drinks. Over time it’s become so reinforced that people are scared to order anything other than the most well known drinks.

If a chef school taught its students this way, every restaurant would be a fast food burger joint. But most schools that teach cooking try to instill creativity into their pupils. Experimentation is what makes dining out a pleasure, the same cannot be said about most bars.
—Darcy O’Neil at Art of Drink

This comes from a not overlong and very thoughtful piece. If you are either a bartender or a budding cocktailian, you should read it.