Binding of Isaac has lots of gruesomeness (and you liked that, right?). Granted, it fits thematically with that game.
I enjoy the mechanics, but I really hate the theme.
Granted, I love the theme in Silent Hill 2 and the gruesomeness adds a lot there, so it just depends. In various other games like Dying Light or Left 4 Dead I'm mostly indifferent.
If it would sell more copies, would you add gore?
Nope.
High-level question, when you are making games, do you ever consider pandering (catering to a wider audience, perhaps at your own fun expense or morality) to sell more copies?
Sure, there's some pandering in every game. Never on a morality level thus far, and I hope I don't have to do that ever. Not that I find gore to be immoral in the first place. But there are typically a variety of features that get added in order to sell more copies, sure. Typically not at the expense of my own fun.
But I mean: if I didn't care about selling copies, no tutorials need to go in there, right? A load of the settings can be removed -- play the way I play, or get out, right? Ease of use and accessibility can be ignored. Etc. But instead we think a lot about ease of use and work hard on tutorials and in general try to make it easy to pick up but hard to master. Sometimes that steers features, but it's generally from one fun thing to a different fun thing. And when it comes to settings, you know I like those -- there are loads and loads of them that I have absolutely no personal stake in, but which let other people play the games the way they want to play them, so I'm happy to add them.
I suppose in AI War there were some cases where I had to make some sacrifices to my own fun, but it wasn't to sell more copies -- it was to balance. Certain things were fun the way I used them, but abuseable the way some folks used them. So those had to be nerfed in order for the game to still really work. Sometimes that meant a playstyle that I really liked died out over time, for example. But that's a balance thing, not a sell-more-copies thing.