Southern Seminary had their own panel discussion on the topic of multi-site churches, which has spawned much discussion and debate.  I do think clear and biblical arguments against multi-site campuses have been given, so I am not going to rehearse them.  You can read a few here:

John Meade

Thabiti Anyabwile (very pastoral)

I wanted, however, to make an observation.  It seems that many who argue for multi-site campuses and who argue, biblically, for the necessity of eldership in the local church speak out both sides of their mouths.  What I mean is this, an argument for eldership in the Church is based upon the regular practice of the NT church.  Throughout the NT, churches were governed in some way by male elders and they were given the task of shepherding the flock.  Since this was the normal way in which the apostles set up local churches, then it should be normative for churches today.  Many on the pro-multi-site church debate argue for biblical eldership this way, yet do not apply this same sort of reasoning to their understanding of how a local congregation should gather.  The normal way in which the NT church functioned was to “gather together” – since the meaning of the word Church in the NT is “gathering.”

At the end of the day, it seems like pragmatism.