that's just them special casing it so that they can avoid calling it a mental illness.
It's a persistent delusion fed to you by your parents, your parents feeding you it doesn't change that it's a delusion.
If someone raised their children to believe the tooth fairy was real and that everyone was going to lie and say that it wasn't and that you have to believe anyway, that'd be a delusion, but religion is special because...? the only difference is that more people are doing it.
The only reason for the cultural exclusion is because they don't want to define religion as a delusion, not because it isn't one. It meets EVERY single other criteria.
That's what i'm saying, the reason that cultural beliefs aren't allowed to be delusions is simply because they don't want to make religion a delusion. It's common, so, it's not a delusion. That's the end of the reasoning. Should we really say that anything that's commonly believed isn't a delusion? I think that's an exception made for a logical reason, it defends the field of psychology from culture, but cultures can share delusions.
The reason this exception exists is precisely as i've said, they've special cased it because they don't want to define religion/cultural beliefs as mental illnesses. The very reason for this exception is because they don't want it to count, not because it doesn't meet every single other (much more important might I add) criteria.
they're essentially going "yeah, these are delusions, but uh, enough people believe them and we don't want to piss them off so here's an exception"
I personally don't think that's valid at all, but I can see why they'd do it.
Just because a delusion is normal to have, doesn't mean it shouldn't be a delusion.