You are right, I pushed the mountain biking example too far for it to fit road biking. I understand that cyclists riding perfectly, even disciplining other cyclists for riding badly, won't either eliminate or even reduce incapacitated blindness to, effectively willful ignorance of or irrational anger towards cyclists - the fact that I mentioned a whole raft of other reasons behind bad driving should have made that clear.
At the same time, I know a good number of folks who moved to Santa Cruz, or Palo Alto, or Ithaca, or Amherst, or Davis, or Arcata, or Portland and Seattle, or Boulder, or even NYC with seriously pro-cyclist and cars/drivers-are-the-problem-even-though-I'm-a-driver-more-often-than-not commitments who subsequently came to deeply resent and fear the high-risk riding habits of cyclists-in-general since, as they saw it (and as happened to me in Santa Cruz), a good enough number of cyclists rode in ways that put drivers at risk of hitting/killing them as to really freak drivers out. Even though I think driver asshattery towards other drivers, cyclists, and pedestrians isn't sourced primarily in experiences with driving, cyclists or pedestrians, is it unreasonable to find that youthful, largely male, often petrochemical-rejecting, physically over-confident risk-celebrating bike riding doesn't exacerbate the already existing problem? That was the extent of that aspect of the wider argument I was making.
I don't know a single leftist who thinks that leftists acting perfectly will draw the public to their side. I know a lot of liberals who do.