Well, first, yes, really: you absolutely were blaming things on the rise of secularism. Maybe it's not precisely what you meant to convey, but the way you phrased it in your article did not leave any reasonable room for doubt given a conventional understanding of what the words meant: "In a progressively secular society, fundamental ideas about the nature of humanity that are deeply rooted and easily accessible in religious thinking, are slowly degraded". You here are clearly linking--in a way that is only used when we should imply a causal connection--progressive secularism detaches us from religious thinking causing a degradation of our view of humanity.

You might be right about the consequence, but if so, I don't think it has very much to do with the reasons you give--I'm not sufficiently motivated to try to give a compelling case right now, but if you've read The Righteous Mind by Jonathan Haidt you'll have a good idea of what my arguments will sound like, and if you haven't read it, you probably won't be convinced by my arguments.

However, the bottom line is that actually nobody can articulate arguments against cruelty very effectively. Anyone can come up with a simple and unconvincing (to anyone else) rationalization for why to not be cruel or for why to be cruel, and almost nobody can formulate their arguments to withstand scrutiny. This simply shouldn't be the standard by which we judge.

For instance, practically anyone can come up with a personal anecdote about why they don't like this kind of thing (if they don't). For example, on letting the unvaccinated perish, you can quickly say: no, you can't do that, because people have a right to life even if they make some bad decisions. The foundation of human society is acknowledging that we all have this right."

If you start asking people to solve the problem if evil (religious) or present empirical evidence for the existence of any meaningfully compelling "human right" (secular), they're mostly not going to be able to manage it. There aren't very many Christian Apologists, and there aren't very many moral philosophers.