It does irritate me when I've stopped behind a vehicle at some traffic lights because it's pointless and anti-social to go to the front, and then some blunt of a cyclist wobbles up to the front. He/she then ends up slowing everyone down, including me.
Bit impatient of me perhaps, but why not wait next to another cyclist (me) already there? It's better and safer to be in the queue behind the first vehicle or three, everyone has a better and less stressful transit across the junction that way.