Part of the problem with being a vocal advocate for critical thinking is deciding just which facet of nonsense to spend time fighting. The forces of anti-reality present a huge number of fronts, making triage a necessity.
As an astronomer I of course have certain pet projects; I’ve taken on astrology, Moon landing deniers, cosmic doomsday promulgators, and geocentrists. But a background in science allows me to broaden that approach, and I will happily help shoulder the load to debunk the claims of climate change deniers, anti-vaxxers, homeopaths, and young-Earth creationists.
Some of these present a more pressing need than others, of course. Astrology is a minor issue compared with, say, someone who supports abstinence-only education.
But they’re all there, all the time, creating a background buzz of hogwash, an atmosphere of denial of science, evidence, and rational thinking … and that can have devastating consequences.