In the context, yes: you're teaching kids that someone else will be protecting them from harm, so long as they obey arbitrary rules and restrictions. That's the exact mindset someone needs to have to be susceptible to a cult, and the exact opposite of the mindset needed for responsible interaction with the general public, either in person, or over a network.

Better they be taught early that nobody can offer them complete protection against all harm, and show them how to protect themselves.

Denying them access to because you can't control what they see, or how they will use it? That sounds like the behavior of a cult leader, not a parent.

And you think the best things for developing minds to exposing them to these groups because according to you "it is just marketing".

I think that by age 10, a kid should have a debit card and begin making some of their own purchasing decisions. I think they should be learning to budget their money early, when mistakes cost them tens of dollars instead of thousands.

And before that, they need to understand the very kinds of marketing that you are talking about. They need to know that advertisements are inherently deceptive, and to evaluate them critically. Your "Delores Umbridge" approach to teaching defense against the "Dark Arts" of marketing isn't going to cut it: they need direct, actual exposure.