Quantric Foundry, an analytics outfit focused on gaming, has published a report breaking down some metrics about competitive videogaming. While it seems intuitive, the results of their report confirms that the older you get, the less competitive multiplayer will appeal to you. While there is a difference between when genders fall out of love with pwning noobs, the most significant factor was age. At about 35 years of age, most players cease being concerned with their kill/death ratio and winning matches and shift their gaming to single-player or cooperative fare.
If you no longer care about smack-talk and jacking wins from scrubs, congratulations! You made it past your twenties. You probably curse less in public and have responsibilities.