< Another set took Zuckerberg entirely too seriously:
I am not a stock market
person but the fact that
Facebook’s stock hardly
budged on a day that Mark
Zuckerberg said he planned
to pivot the company to a
totally untested new
business model seems odd
— Casey Newton >
People keep saying things along those lines.
Based on the number of healthy non-it-specialist communities I saw (that still stay there as long as possible) I don't think that is the explanation, except if you mean the initial launch.
My explanation is a giant PR mistake where they tried to push a botched identity consolidation at the same time and with the same name as their social network.
Ironically they later came back and fixed the identity problems and usability wise it became one of the better ones IMO. (I'm talking about keeping different groups of people separate, not protecting against TLA agencies.)
In the end we should probably be happy: they could have owned social networking in addition to mail and search.