At one time, there was a sensible reason for making it difficult to fire a federal employee. In theory, civil servants were not partisan and they were not supposed to be affected by the political ideologues who we appointed to run government agencies.
The ideologues were prevented from firing those who wanted to do a non-ideological job..
It worked for a while, but if you keep someone from being fired for political reasons, eventually they figure out that they can f#ck off on the job without penalty. I guess the powers that be decided that it was still better than a politicized civil service - or else they didn't notice or didn't give a damn..And today, we do have a politicized civil service. (Look and all the 'loyal bushies' in the Justice Department..