"Cultural mindset" isn't an action, it's a concept that lives at an abstraction level well above morality. What specific action is being taken that you believe is immoral?
It's hard for me to see how the moral principle that men and women are equal [1] is being violated here. Any child is free to play with any lego (as the article demonstrates) and the company selling them has no control over what the children do 18 years later or even what toy they use now.
[1] I assume you mean equality under the law. But if you mean some different sort of equality it would help to state which.
[edit: not sure why you are being downmodded. I don't think your explanation was complete, but it's certainly helpful.]
