Oh, I was talking about kids who still don't understand what's right and what's wrong like preschool kids since Toku shows like Power Rangers and Super Sentai are meant for them. There are kids that's smart enough to understand so maybe it's safe for them, but there are also kids who don't. It's not that kids shouldn't watch Toku shows, I think it's safer to let them watch Toku shows when they're old enough to understand or at least under their parent's guide.
I should've clarified that toku shows are best watched for kids when they're at age 7-10. Pre-school kids aren't supposed to watch toku because they can't read subtitle at that level (kids developed their reading skill at age 5). Normally, according to the studies about subtitles, the age range for kids to practice reading using subtitles is 7-8 years old. So that would make sense for kids at that age to watch toku.
I apologize if my thread didn't clarified on that.