I think a better way to put it is, sufficiently complex social software doesn't work on an MVC model that was originally developed primarily for single user int

I think a better way to put it is, sufficiently complex social software doesn't work on an MVC model that was originally developed primarily for single user interactions. I've encountered it in my work work on ultra large social projects. The complexity and number of states created from so many players leads to a mess of user journeys and exponentially more code. But in my experience this is more of a product design problem than a architecture one. Social software is funny in that two user clients can technically work fine but social bugs can still arise due to poor design. Sorting these out requires a great deal of care in the initial product design and goal setting, the later complexity problems in the code being an outgrowth of this stage.