I'm not sure your underlying premise is correct, though. The 1960s weren't the only major doctrinal shifts in the church; just look at what things looked like pre- and post-Augustine. Instead, I think the Catholic Church remains strictly *because* it's been willing to adapt over the centuries.
Meanwhile, my reading on the statistics on religiosity and what-not is that people aren't actually becoming more atheistic, there are just fewer and fewer who feel at home in many denominations as they currently exist. Clearly there are needs here that are not being met.
I'm curious, what do you think those needs are? What adaptations to you envision for the present era?