Competitive & cooperative multiplayer components of video games have a lifespan that is typically decided on popularity. After a long period of time with little to no player base, the company in charge of the game will usually shut its servers down. This is very common with annual sports games, as the previous year's game tends to becomes less popular after the new version is released.
Electronic Arts maintains a full list of their games that have had servers shut down, and releases a blanket statement whenever they announce additional titles:
"The decisions to retire older EA games are never easy. The development teams and operational staff pour their hearts into these games almost as much as the customers playing them and it is hard to see one retired. But as games get replaced with newer titles, the number of players still enjoying the older games dwindles to a level -- fewer than 1% of all peak online players across all EA titles -- where it’s no longer feasible to continue the behind-the-scenes work involved with keeping these games up and running. We would rather our hard-working engineering and IT staff focus on keeping a positive experience for the other 99% of customers playing our more popular games. We hope you have gotten many hours of enjoyment out of the games and we appreciate your ongoing patronage."
PC games can occasionally live on after a publisher decides to shut down the official servers. For example, the servers for Tribes 2 were shut down in 2008 after Activision bought Sierra. But the community was passionate enough to release a patch and restore servers for online play the following year.