For counter arguments there's some fascinating stuff at http://limuxwatch.blogspot.co.uk/ although it hasn't been updated for a while, so maybe they've finally succeeded?
1. Completely anonymous - who is this person who has dedicated a site just to this topic?
2. Clearly neither German or even speaks German (using Google translation!) - so, we can rule out an insider or even a user.
3. Railing on all topics relating to Linux for government use anywhere on the globe without giving reasons other than quoting other sources.
As I said, not reliable and someone clearly disgruntled with no independent information or expertise (technical or managerial).
Sounds like a disgruntled vendor.
Either way, a 9 year IT project is really dismal.
Measuring the success of an IT project in years is wrong in any case. Success is defined in meeting your goals at the required time. Munich is a little late and they have had their own share of issues and roadblocks, but all in all they met their goals. Considering that this was the first large scale migration of a city administration in germany, that's not dismal.
And perhaps you would work through this sort of multiyear migration plan, but I certainly wouldn't. From what I can tell the project was driven by feel-goodisms and not at all properly scoped.
Added to that is the fact that the migration happened department by department in multiple steps, one done, next started. So yes, it's a multiyear plan and I do agree, I would not have planned and gone through that plan but calling it a failure because someone actually had the guts and vision and pulled it off is a bit far fetched.