Zuck will have fun explaining to the shareholders why they are spending money on this and not trying to get back to their IPO stock price.
Zuck has 57% of the voting rights so listening to shareholders is a courtesy on his part.
Facebook's new engineering campus is a judgement call. To argue that he's wrong, you basically have to argue that you're better at making that sort of decision than he is.
Where's the evidence for that claim?
They might look at this as frivolous waste of money that should rather go towards "restoring" Facebook's image that has declined in the past months.
I think this is fantastic and I look forward to seeing the outcome of this, secretly envying the employees from my cubicle :)