Yep - I was in civil service for 15 years and had cause to fire two - the "easy" one only took 10 months and two prior years of documentation....
Its not that hard to get rid of people for cause, the problem is that many managers are simply lazy and don't know how to build a case.
Getting rid of poor performers is a challenge because many agencies have agreed to binding arbitration in their union contracts.
I believe this should be illegal because the government does not have the authority to negotiate away its responsibility to manage its workforce.