Organisations fear the apparent messiness of internal use of social tools. They fear the possibility that people will waste their time. They fear the risk of dissent and disruption. These fears are raised and articulated in this article from Oliver Marks.
I would refer, yet again, to the wise words I once heard Vint Cerf utter about the Internet, namely that it is just a thing. If you don't like what you are doing with it is a reflection of you as an individual, an organisation, or a society and those are the things you have to deal with. The same is true of intranets.
Isn't it better to see our problems and disfunctions and be able to deal with them rather than have them hidden and festering? Isn't it better to find out who your corporate morons are than have them sneak up on you unawares? Isn't it better to be able to see, quantify, and deal with your time-wasting and manage it. Isn't it likely that these tools can make the job of management easier rather than harder if we just embrace them and understand them?