Why do they state that Linux is still difficult to use? What difference would it make to the majority of office workers, if the main applications work (email, browser, office)? I think none. OK, I have heard that Open Office Spreadsheets can not yet compete with Excel, but other than that?
The chair of my department at a research hospital is a big open source advocate (actually, it's more like a big hatred for Microsoft). Most of the staff does great, professors, programmers, but the admins struggle because they have to interact with so many institution-wide systems that aren't designed with cross-platform interoperability in mind. Thankfully, things are slowly getting better, but this is definitely a roadblock on the road to widespread adoption.