It's only targeted at girls if you believe that girls (but not boys) respond to female characters and themes of friendship. Similarly, regular lego is only targeted at boys if you believe boys (but not girls) respond to building stuff.

I have no trouble accepting the belief that boys and girls are different, and that building products which disproportionately provide utility to girls is beneficial. But if you disagree with this latter claim (as bonaldi seems to), then Lego is not actually targeting girls - they are merely targeting people who like friendship more than building stuff.