Civ 4 is terrible.
1. Bad graphics. Civ 4 looks like it was made during the Bush years. The units are ugly, the terrain is all messed up looking, and the interface is nausea inducing.
2. Squares. The square tiles are lame. I want to play a strategy game, not Sid Mieir Chess.
3. Stacking Units. I'm supposed to believe 400 tanks are piled up on top of each other all the way to the moon?
4. Religion. It doesn't do anything as all religions have the same generic abilities. Boring.
5. Health. Oh fun, micromanaging city sanitation.
6. Road spam.
7. Vassal states. Blah.