I think you can only blame it on the writers. It seems to come from a rather immature, pop culture idea of history and how things work (and such ignorance seems prevalent in perception of the WW2 era especially; this is where you get popular ideas like that the Nazis could conquer the world, that the Japanese could defeat the US, that the Depression was wholly ended by the war or that war is good for an economy in the long run, that the Germans were light years ahead of everyone scientifically, and so on, and so on and so on).
Fascism had many pratfalls to efficiency. For one thing, you had a number of insane pet projects going on all the time, and funding and positions were all based on the whims and personal affiliations of the Dictator. For another, the pseudo-science and bigotries of the state and ideology were always undercutting things. Part of the reason the Nazis failed to make an a-bomb is because much of the knowledge of it was labeled "Jew Science" which was not real Science to the Nazis, and which they ignored or replaced. And for another, Nazi Germany's success and recovery was very hollow. Without constant war and expansion, the economy would have collapsed, along with any other progress. So, in short, it eats itself.
If Nazism were efficient, the line of thought would be somewhat reasonable on Gill's part of having a Nazi style state, but not having it be a bigoted state. But it's not so.