yes, that was a neat trick that so called open ooxml document format from ms.
like john a already stated, a big part of the problem is caused by public services like schools, universities, governments, and the like. they use closed source software because it comes shipped with the hardware.
and what's more: the i.t. decision makers often like to stick to what they know, just to be on the safe side, career wise.
changing that would require a lot of political influence (or just brute power) to forbid the ongoing abuse of tax money on closed source software.
so if a government / educational /public organization or whatever, forces you to use a certain (closed) document format, they should provide you with the means to do so.
but alas, even in germany some departments who were working with open source software are switching back to closed source software.
the reason was that users were complaining about incompatibility of the aforementioned so called open ooxml formats...

added:
some serious
marketing also could help. like a range of desktops/notebooks/netbooks/tablets etc. from a well known brand.
thus giving users a choice when buying a new computer. show people what linux has to offer, like in computer stores and the like. it even saves money on the os and on (expensive) applications.
a nice side effect from the latter would be a decrease of the illegal use of (professional) software by home users.
breaking the hegemony of the closed source world still will be a pretty hard.