Simple. There's people who ascribe the term "evil" to each of those concepts (yes, even potty-training). They have, in some cases, equally emotionally-charged opinions about secular humanism or potty training as Nadaka seems to have about religion. They would claim that those things cause "severe mental, emotional and ethical harm". They could even back it up with some anecdotal evidence ("I grew up in a secular-humanist household", or "I grew up in a household that potty-trained"), or some statistics (there's an awful lot of criminally-minded individuals out there who commit a lot of evil who have been potty-trained).
Hopefully, most of us would see right through their arguments. But, for some reason, when people start talking about the "evils of religion", we don't see the same holes in those arguments that we would see in a similarly-constructed argument about the "evils of potty-training", the "evils of vaccination", the "evils of wi-fi radiation", etc. Nadaka's argument is high on the same sort of hyperbole ("it imposes a severe mental, emotional, and ethical harm", "inflicting the communicable memetic disease", "the child never recovers") that often comes from the "anti-everything" crowd, but pretty short on data to support some pretty over-the-top claims.
Now, none of this is to say that Nadaka's "fundamentalist christian" upbringing DIDN'T have any hallmarks of mental, emotional, or ethical harm, or even child abuse. Perhaps it did. It does happen. But to paint all of "religion", or even all of "fundamentalist christian" with the same brush is rather poor reasoning.
