That's just ignoring history. There are plenty of good reasons to hate the Nazis without needing to do that.
In the similar way, it's not necessary to dismiss Soviet Union's early modernization successes in order to blame them for their crimes against humanity.
Honestly, this shit needs to stop. Acknowledging that some fascists have been good at something at some point does not detract in any way from being anti-fascist.
If you claim that fascist are dumb, stupid and can achieve nothing, what do you think the masses will think about your message when the fascists turn out to be competent? They will wonder what other things you are wrong about.
So I say to you: stop being a fascist enabler.