MSZ
Banned
Germany already spends quite a bit keeping the few federal government offices in Bonn. Having the entire government distributed would mean massive inefficiency of scale.
Would it? With modern communications technologies I would not think the problems would be so great. Why couldn't paper correspondence be erplaced by e-mail? Government meetings being held via teleconference? It would be hard, sure, but not impossible.
And there is the problem of Capital cities often becoming too powerfull compared to the rest of the country. Political power attracts financial capital which attracts job opportunities, all at the expanse of the rest of the state. Germany might have less of a problem with that since it is a federation, but a lot of people from other countries tend to have negative feelings towards the people from the capital for that reason. Spreading the ministries out could diversify economic development more evenly.