I don't think he (or many) would claim otherwise. The issue isn't the people who ride bikes, but rather the mode they choose to travel with and the impact it has on your drive. Bikers cause all sorts of added danger to both themselves, and you as a driver.
If you have a moment of human error in car-v-car, you're very likely to have both parties walk away from the incident. You call your insurance(s), your rates go up a bit, and your life moves on. Accidents are very, very common.
Repeat this same scenario in car-v-biker, and the odds quickly swing towards it being a life endangering accident. It's just a step away from hitting a pedestrian.
I don't dislike bikers because they slow me down or anything like that. I dislike them because of the likely increase in severity for almost all car-v-biker accidents.
edit: Interesting, seems i am getting downvotes for my opinion. Care to explain your thoughts? I can't imagine you (downvoters) feel that car-v-biker is an equal risk compared to car-v-car, do you?