For "games" in general, there should be different types - some more complex than others so that people who want different things can have them. Everything being the same is boring.
For a specific game, it's a matter of finding their audience and giving them what they want in such a way that the game is profitable so they can give their audience more of what they want. So no, games shouldn't simplify just in order to reach more people. If designers want to make a more complex game and they find an audience who will buy it in enough quantities to make it worthwhile, more power to them. It depends what the game designers want. Obviously 5e, for example, needs to corner the largest share of the market in order to maintain its status as leading brand, so it's in WotC's interest to make a game that appeals to a larger slice of people. Another company, however, doesn't have the same needs and so has more freedom in what kind of games it releases.
As for offending people, I have no idea what that has to do with mechanics, simple or otherwise. Unless you're talking about the spell design rules in original Torg.