Granted they're different type spectator sports, but The Show, NBA2K, and [former] Live's crowds add immensely to the overall ambiance of games being played. It just makes it more immersive. Not making appropriate improvements to the elements surrounding the players make them seem as if they're playing in a fishbowl imo. There's just too sharp a contrast between the players on the field and what surrounds them, and it stands out. Other games/devs have realized they needed to get away from that effect