The GP's point still stands: closed offices _may_ make for more productive employees (for some classes of employees), but it is not obvious that they translate into a more productive _business_.

Instead of using Trello, you could compare Atlassian against Fog Creek. Fog Creek was founded two years before Atlassian, and both companies are more or less in the same space - they make productivity tools for developers. And yet it's hard not to look at Atlassian as the more successful business so far.