If it werent pink, they would have gotten more sales from it. Boys would be ridiculed by other children for wanting girly looking playmobil, dads might be reluctant to buy it for their sons, etc.
While in fact its a theme that could appeal equally to both boys and girls.
Personly I'd love to see a playmobil version of "the cocoanuts" using the hotel, including clickies that look like the marx brothers.