The annoying qualities people feel about "hipsters" are the facts that 1) they want attention for being "creative" or "rebel outsiders" even though they are not at all creative or outsiders; and 2) they avoid taking risks by being overly saturated in "irony" - if everything they do is ironic, nobody can make fun of them...the retreat to irony is a sign of weakness and unwillingness to take any kind of stand (moral, aesthetic, or what have you).