I also think it absurd to presume that there's zero benefit to having folks face-to-face from time-to-time.
Wanna work from home 4 days out of 5? I say go nuts.
But I would want some amount of face-to-face time, not to see asses in seats (which seems to be what every work-from-advocate assumes... as though there's no other concerns beyond accountability, a strawman if I've every seen one), but because it helps build team camaraderie.
I've seen this first hand. I'm the Product Owner for geographically distributed team. Skype is used heavily as a mechanism for the team to communicate, but we also include quarterly face-to-face get-togethers where the team can sit in a room and whiteboard problems, pair program, or really whatever they want to do that feels useful.
The first time we did this everyone, every single person, raved about how valuable the activity was. Not because they were inherently more productive, and certainly not because they were being held accountable. Rather, the simple act of people in a room together further cemented their bonds as a team.
Humans are social animals. We're used to physical proximity as a component of communication. Hell, the NYT had an article about why it's hard to make friends after 30:
http://www.nytimes.com/2012/07/15/fashion/the-challenge-of-m...
Two of the three are proximity, and repeated, unplanned interactions.
That's just not possibility in a 100% remote working environment.