When I think of Amy, river and Clara, the one thing they have in common is that they are all strong female character's who all delight in being bossy with the doctor and putting him in his place. If anything his women are a bit too in charge. Have no idea how anyone could look at those character's and say their creator was sexist. I would say it's strong males he can't write like rory. in fact the whole Amy - Rory dynamic is the ultimate non sexist relationship, unless we were talking about sexism against men. She's blantantly in charge, while he's sort of a 'yes dear, I'll hold your purse' type husband