Hipster culture is a reaction against perceived cultural trends of inauthenticity and superficiality. In a hyper commoditized world where commercial motives permeate every layer of the cultural fabric and advertising and lobbying dollars make everything in mainstream society suspect or of questionable motives, hipster culture has arisen to offer an alternative set of values and attitudes.
Calling someone a hipster (or a bro, or anything, really) is easy until you understand their motivations. If people were more ready to ask about why someone enjoys what they do, there would be a lot less name-calling, I think.
What is a Hipster? (via Reddit)