Plenty of people are told how they should write their books actually but that's neither here nor there.
And yes I could not buy his books (and I don't) but I can also mention that I have a problem with it. He is, after all, under no compunction to change his work for me, no? 1. What's more I have no interest in living in a world where I pretend that the media we consume and choose to consume does not influence our attitude and thinking so if the chance arises I will mention that I find the way someone chooses to represent something as problematic or 'not to my tastes.'
Well that's true offcourse... but thankfully you rarely see the kind of public focus and pressure on authors before releasing a book, that eg. the videogaming industry is under.
1. It does, but only very slightly. A normally intelligent and mentally healthy adult will not change his/her's fundamental beliefs and/or morals over any book, song, game, movie and what not.
Those fundamental beliefs and/or morals are shaped much, much, much more through constant daily interactions with family, friends, classmates, coworkers and so forth.
So no... games do not make people violent/sexist/x, as all reputable studies have shown.
If you really wanna change things for the better, you should argue for timely and effective treatment for mental illnesses and better checks on child welfare (trust no parent? theyre gonna screw up?).