meh. It's overstating a stereotype and turned on boys.
IMHO, the worst stages of gender stereotypes being pushed on kids is in the pre-teen/ early teen age bracket, and the pushers are their peers.
The author also completely skips the fact that both genders have issues with gender roles being pushed at them.
Emily hated dolls. She still doesn't much care for them. She likes pink and purple, but also blue, orange and white.
I had a sociology professor who had a 3 year old boy who's favorite color was pink. The kid loved pink. No one is worried about Emily's obsession with tractors or cranes (construction, not the birds) but my sociology teacher was concerned that her son would be teased if his favorite color stayed pink.
If anything, these days, boys have it worse in terms of gender stereotypes for likes and interests than girls. It has become acceptable for a girl to have more varied interests, even considered "cute". Boys? Not so much.