The technologies we use to communicate evolve fast, and I would bet money on the fact that (probably because of mindset evolution and tooling) developers are now more efficient when working remotely than they were ten years ago. Moreover, as we are on HN, we are not necessarily talking about average developers, but more about the ones that are used to Git, IRC, Trello, and other tools which make remote work more doable.
Startup environments are not average, and this must be why companies like Github and 37signals can be successful while having remote workers.