The line is not imaginary. See this very thread for examples of people bullied for choosing the "wrong" toys. If you build a toy that more girls than boys like,

The line is not imaginary. See this very thread for examples of people bullied for choosing the "wrong" toys. If you build a toy that more girls than boys like, that's one thing. If your marketing says (either implicitly or explicitly) "this toy is for Girls", kids will pick up on that, and they will enforce it too. The results last lifetimes. It results in adults unable to even see the exclusion as anything more than "grouping by appeal to typical girlish sensibilities". Which views they in turn pass on to their children, continuing the cycle. Think about the world you want your daughter to live in. Do you want her to be told that "hacking is for boys" because tech appeals to more "typically boyish sensibilities"? No? Then look for the fundamental gender discriminations bullshit like that rests upon.