The n00bs - oh, man. I work in a college town, walk to work (it's literally too close to bike and get any exercise - sometimes the things are too dang efficient) and it's that time of year when the kiddies are filtering back to school. Hooboy. Nothing worse than a n00b weaving the entire width of the sidewalk fiddling with gears with a bike lane eight feet away, unless it's an adolescent fool on a BMX who thinks he's still in junior high school and the world is his track. Serious riders will cross the streets to avoid these idiots. Serious walkers don't even have that option.
Then you gotcher Critical Massholes. These are guys - yeah, it's nearly always guys - who have chosen what they consider a virtuous lifestyle from an environmental perspective and actively intend to make life miserable for anyone less virtuous, and that includes other cyclists. "We aren't slowing traffic, we ARE traffic," goes the slogan, and then this "traffic" decides it doesn't need to obey traffic laws and becomes "pedestrian" whenever it feels like it. Yeah, traffic, right.
Neither category are serious cyclists, although the CM'ers are very often skilled ones. The word "serious" connotes some recognition that there are other people in the world and that transportation is a cooperative, and not a competitive activity. A quick re-scan of the article reveals that half of the problems listed are serious cyclists calling the jerks out and getting swung or cussed at for their trouble. The cyclist who thumped the jerk with his own bike lock may have been over-reacting a bit but he has my sneaking sympathy.
Believe it or not, we can all get along, or at least most of us can. I guess.