You only have to look at half the discussions on HN to know that humans are still very religious about subjects despite the rejection of the supernatural. We joke about language or editor wars being "religious", but really, that same thought process exists.
On the same topic, but contrary to what you are saying, organized secularism with rituals, values, expectations may only draw out this natural propensity towards "religion" in people even further.
Touching on your point further, Protestant churches actually fare pretty well with some of these cultural issues that force change. If someone disagrees about gay marriage or another controversial topic, they just start a new church and half the congregation goes there. It makes Protestant churches at the same time possibly more extreme but also much more varied in their belief systems and allows for religion to evolve. (This is not an endorsement of Protestantism, just an acknowledgement).
I dislike the notion of organized secularism because it creates an us vs them attitude. You have churches and then secular churches when the real solution (whatever it may be) should be a less dogmatic form of outreach that grabs at people from all walks of life and engages them. That's how people change, that's how they get better.