You can judge if you want; however, you can't tell just because a 9 year old can't recall the meaning of those holidays that they've never been told.
I know of quite a few things I told my kids regularly when they were small that when asked at 9-10 they wouldn't have automatically recalled without at least some prompting - including things we did regularly at home.
How adults view and value the world doesn't mean their children do in the same way. It's great to talk about things, that doesn't mean our kids will value it the same way - that' why there are so many of us who don't share a worldview with our parents.
This is despicable. Lots of terrible things have been done in the name of religions. Don't generalise from the depraved actions of a minority to the vast majority of normal people who have the same religion. Pretty sure there's a word for that?
Those acts weren't just done in the name of the religion - they're done with the institutional power of that religion. Those who do those acts are protected by the power of that religion within the cultural setting they are in.
When we take the religion out of it to save the feelings of the 'vast majority', we silence the victims. When we play 'no true scotsman' and pretend the perpetrators aren't really of that faith, but are only in name only, we erase why they were able to be perpetrators in the first place. And it placates the very people who should be challenging that minority rather than what happens so often - look away, blaming the victims, pretending it's another denomination's problem.
And your evidence for that is ??
That Religious Trauma Syndrome is known to impact those from mainstream religious groups, religious abuse can happen to people in any religion or faith. the documentation on apocalyptic anxiety, including rapture anxiety, can be seen in people in mainstream faiths, and that mainstream faiths - including the CoE - have written and discussed the perpetuation of spiritual abuse within their own ranks and even come out with training for staff, acknowledging it's a on-going issue to be aware and mindful of watching for in other staff.
There has been abuse recorded in UK at some boarding schools, within the Scout Movement, in the Armed Forces and even the NHS. That doesn't mean that these organisations are evil or corrupt, just that sadly some people aren't honourable.
And people complain about, openly mock, and discuss their complete lack of respect for boarding schools, the Scouts, the modern military, and even the NHS, along with every other institution and what they stand for. That's not calling them corrupt or evil, it's just not having respect for them often from their own experiences with them. The veterans I know are the loudest and the most unsubtle in their protests against the military and government policies.
Every institution leans to corruption without vigilance and challenge. That's how power accumulation tends to work. Those who've left can be part of that vigilance and challenge, institutions should learn from those who choose to leave and lost respect for them - but instead, certain institutions train people to see those who leave as apostates who are damaged and that the problem with the institution is just a few bad unhonourable apples, ignoring that a few bad apples absolutely can spoil and rot away the entire bunch and damage the entire purpose of an institution in trying to protect themselves from challenge.
Jesus was quite happy to challenge, mock, and openly be disrespectful of religion, and that's treated as a wonderful act against corrupt faith leaders and twisting of the faith by those in power. He literally overturns tables and chases people with a whip of cords for what was a standard practice - most people couldn't travel with their sacrifices so bought them in the courtyard of the Temple before taking them into the Temple - because he viewed that practice as corrupt. His words against them have meant that many people - including Christians - don't know what a Pharisee or Sadducee was or who they became, something that was once a major religious-political division in Judaism for centuries has been reduced culturally to synonymous with corrupt religious people because of the Christian texts and how they've been used. Christian apostates being open about not having time for the faith and mocking it as a fairy tale is a pretty mild challenge in comparison. If Christian apostates are damaged and in need of healing for that, what would that mean about Jesus? If we're meant to do a Jesus would do, what would that mean for how Christians should be acting towards the corruption and abuse in their institutions?
Is there something about Christianity that makes it fair game for criticism, and trial by Mumsnet?
That something is Christianity having been and in still regards still does have significant institutional power where many Mumsnetters live, even if it's not as much as in centuries past. Most people are criticising their own experience of Christianity. More people in the UK and Ireland will have direct experiences of Christianity, even if it's only within schools, compared to other faiths because of that remaining institutional influence.
I have criticised Islam, Judaism, neopaganism and related faiths, based on my own experiences within those communities on Mumsnet. I wouldn't do it with Hinduism, Sikhism, or dozens of other faith groups where my only experience is surface level knowing people of those faiths. It's that simple. Even within Christianity, I'd struggle with many specifics in smaller denominations that have broken away from many mainstream Christian concepts, like Quakers - even having been to Meeting Houses and events, reading their literature, I don't have the type of experiences to get into criticism. A few concerns, but too vague to really be able to discuss meaningfully.