Considering the number of people currently using an operating system that is over a decade old, I think you don't quite understand the pace at which large, particularly government, projects tend to move.
Let's see: LiMux was based on Debian Etch (2007) until 2011, when it was moved over to Ubuntu 8.10 (Oct 2008); AzLinux, the sole survivor of similar attempts, is based on Suse 11.2 (2009) and only moving towards 11.4 (2011), but it's still in development. For the record, Windows XP SP3 was released in April 2008. So, "a decade old" OS (2008 in fact) is being replaced by basically OS from the same time period over the course of 8 years and is still in progress. I'm sorry, if I don't think it is impressive.
Eight years for 65% is quite impressive actually.
Regardless, this is quite the tangent...