There are a lot of extremely complex, demanding, and unique systems-based indie games which are very successful. I think you have it backwards - At the Gates i

There are a lot of extremely complex, demanding, and unique systems-based indie games which are very successful. I think you have it backwards - At the Gates is a case of a game simply not being up to bar despite the recognizable name behind it (because the competition has gotten so fierce!), rather than people not bothering with complex games unless they have a recognizable name behind them, and only then for nostalgia reasons.