I would normally agree, But hard to understand visuals (not intuitive) might discourage new players from trying the game. Those that do try the game will have a large cognitive load just to understand what is going on, and therefore will be unable to focus as much on the gameplay (that df is know for). So potential players and new players would be most affected.

Can confirm this assertion. I spent years building pretty games, but often our games are trounced by a rival with by with crappier graphics and better gameplay.

Gameplay only starts to matter once UI and graphics are appropriate.