Most governments aren't decentralized in their structure, which causes the "problem". If you have private entities that coordinate with each other it works quite well, but the world is very used to big centralized governments that "solve" all their problems.
It's a pretty direct response to your claim that "decentralisation sounds nice, but doesn't work in practice". Decentralization has worked in practice many times in many ways.
Also, you can have reputability AND decentralization, that's actually a fundamental component of how any Blockchain system works. When you mine a block you sign it to ensure nobody else can resubmit your work and take credit.
And, so what? You've posted a whole load of nothing.