I don't think that anybody likes this minimalistic rudimentary cartoon style of graphics.
Clearly not true.
False dichotomy fallacy.
Nope. There are at least two ways in which graphics tradeoff with 'fun'.
1. Production - Stardock would have to invest resources (money, people, etc.) into developing photorealistic graphics that could otherwise be invested in improving the core gameplay.
2. Performance - Users with older systems may not be able to run games with photorealistic graphics without performance loss, which may affect gameplay.
False dichotomy fallacy.
You were closer to the mark before. "Games like these need no brilliant graphics in order to be superb" is not the same as "Games like this need to not have brilliant graphics in order to be superb."