I think the Lego Friends set is aimed towards girls, if it gets them interested in construction I cannot see the problem.
Out GD loves the Lego Friends play sets and has lots of them and role plays with the characters. Her brother leans towards the cars and dinosaurs ranges, but will play along with his sister and her Lego Friends as she does with his dinosaur sets.
Our teenage GS is Lego obsessed and some of the kits are upwards of £300.00.
A couple of our DiL’s have the Lego flowers and bonsai sets, they find them relaxing to construct.
I really cannot see the problem with the advertising, all children differ, some girls gravitate towards pink girly things some do not. Some boys are into cars and guns some have their own doll (two of our GS’s have a dolly and pram)