Why Second Life Has the Wrong Architecture

I have been involved in the Second Life community off and on for several years.  For a time I was very bullish on the project and I really thought it might take off and realize Neal Stephenson's Metaverse concept.  But it doesn't seem that it is going to get there.  I thought that if Linden Labs kept innovating they might make progress in that direction, but upon logging in recently I've realized that the whole architecture is flawed.