The 100-friend limit on Xbox Live is being blamed on users still playing Halo 2 on the original Xbox.The Xbox Live online service, launched on the original Xbox, was designed to handle no more than 100 friends. More friends would not be a problem for the more robust service powering the Xbox 360, the continued popularity for Halo 2 demands continued legacy support for the original Live architecture, according to “a high-level Microsoft source” talking to website G4.
It’s not an issue that can be solved with a patch, “or else Microsoft would have released one ages ago.” Ending the friend limit means ending support for Halo 2.
Microsoft hasn’t stated when it will disable the original Xbox Live, but in the meantime Halo 2 will enjoy its top spot on the original Xbox usage charts.