Maybe I'm not talking to the right people or reading the right sources but I generally never hear anything positive about Critical Mass. And from personal experience, I've found the participants to be a bunch of overly emotional, bike-righteous asses who would risk other people's safety just to push their own agenda. I'm frightened of Critical Mass. While driving, I do not want to be verbally or physically assaulted by them and I certainly don't want to accidentally bump into any of them and get sued or attacked! But they want you to bump into them because they want to have the "go ahead" to yell at you, run their bikes into your car, and throw things at you if you yell back! Now, like I said, my experiences have been limited and I'm sure there are peaceful gatherings too but to me, Critical Mass makes me think less of bicyclists than to want to help them with their agenda.
I mean, what's next? Are they going to ride through BART stations to demand that BART allow bikes during all hours?
Honestly, I think drivers make a lot of accommodations as it is for bike riders. With the cycling craze in Lamorinda, drivers often need to swerve to the opposite lane (risking head on traffic) just to make way for the groups of cyclists who seem to think it is OK to ride in the middle of a single lane road. They think they have the right of way and we need to just stay behind them patiently. It's like, DAMN IT, just stay in your bike lane in a single file OK? Don't chat, don't share water or whatever it is you need to do when you take up the entire street. I don't stop and talk to the driver next me and stop traffic....why should cyclists do it? Seriously, these cycling "enthusiasts" think that just because they wear spandex and ride a fancy bike, they own the streets. Look behind you, 10+ cars are blocked because you and your buddies are in the middle of the single lane road.
Sorry, as you can see, this is a sensitive topic. I deal with a lot of bikers and most experiences, whether with Critical Mass or cycling groups, have not been positive.