I was raised without religion but as Bangladeshis we have a pretty rigid culture apart from religion. This is the “what do you teach your kids about stuff.” Here in the United States it seems like most of that is just whatever is transmitted through the Disney Channel and movies. And frankly a lot of that is pretty garbage culture. It teaches people to be self-centered assholes.
Obviously there are many moral people who aren’t religious (and many religious people who aren’t moral). But you can take away religion but you still need some moral framework in its place. And in the US that seems really hard. We don’t have ready-made frameworks for “here’s what you should teach your kids.” Many parents do a fine job improvising, but it’s a lot of work to do it on your own from scratch.