Yep, and then the publishers beat them up for not selling well
there really is no way to win
The way to win is to stop caring so much about things which matter so little. So what if you can't practice your homoloveuality in a video game? The game itself is still fun, is it really that difficult for you to just pretend to be another gender or just not have any representation of yourself or people you know in the game? Or even to pretend that a character who is one gender is actually the other for the purposes of practicing your chosen loveual orientation within the confines of a game.
It's completely unreasonable to treat Nintendo as if they've committed some heinous act in not allowing for same-love marriages within a game intended for a younger audience. Of course I'm not saying that there's anything bad with children knowing about homoloveuality from a young age but it makes more sense for the concepts in a game aimed at them to be something they can instinctively understand without needing to think too hard about it or have it explained to them.
You also have to take into account that the majority of customers won't be these children but their parents and it doesn't take a genius to know that the number of parents who actively fight against homoloveuality, especially the exposure of their children to such concepts, is far greater than the number of parents who actively fight for homoloveuality. It's impossible to appease one without alienating the other and it only makes sense from a business standpoint to side with the loudest voice regarding a situation like this.
