He realized that people's reactions will be heavily influenced by their religious beliefs
To realize is to become aware of a fact. The above clause is not a fact, it's a hypothesis. It's not a realization, it's an assertion. Catholicism forbids birth control, but a majority of Catholics are in favor of it. So even if religion has affected their views to birth control, which is speculative, then that influence has been unconvincing in most cases.
I'm a secularist agnostic, and this article just seems like an excuse to attack religion. To the best of my knowledge, all major religious texts are silent on extraterrestrial life, so there's no inherent conflict between religion and aliens.
To the extent that I am at all concerned about people's reaction to the discovery of aliens -- which is to say, hardly at all -- I am more concerned with how we would handle it on a global scale rather than how any subgroup would react. There will always be naysayers, and (it's worth noting) they may well be right! Should it happen, alien contact may well turn out to be a tragic event in the story of our species. Or it might be a monumental achievement. But aside from some ground rules, like not shooting first and asking questions later, I think it makes sense to wait until we know what we're dealing with before making any policy decisions, let alone worrying about the effects of any dissidents, or the motivation for their dissent.