If Ubisoft kept the crew (and others) on your account post-shutdown, people could create community servers much like they have for Titanfall and others.

Piracy allows software to be controlled by users, not publishers, in a way that if there was legitimate support for it people can still reverse engineer these games to support them.

Gran Turismo 4, for example, can only be modded and given online functionality through piracy (mods require a version of the game used as a beta test for some features so it wasn't widely sold).

Piracy isn't the only tool in maintaining discontinued games, but it's fundamental to people who may want to develop alternative servers for them.