Implying there is a reason. In that "Top Ten Things You Didn't Know About Vader's Suit" video, they pretty much confront this directly. They mock the idea that the world of Star Wars has any coherent set of rules to it, and that it isn't just a mishmash of visuals slapped together to create a certain visual effect.
It's just for visual effect. They even made a stormtroooper a real character in the sequels, except whoops, him being a stormtrooper has literally zero relevance for who he is as a character and factors into nothing at all (except a few janitor jokes and plot points which could easily have been written differently). He could have been some random dude just as easily.
They should have made the First Order more like a brownshirts-style paramilitary with, you know, ideas. But I guess when actually confronting the Nazi/fascist visuals you're clinging to, you're placed in the uncomfortable place of genocide, trauma, and human evil of the most profound sort, so you can't sell your toys anymore to wine moms. Or, I guess your bad guys still can genocide, but it's not really projected as a bad thing? I'm not sure what TFA says about it, the movie makes no sense.
I mean, we've brought up this before, but:
If Star Wars made any attempt to be coherent with its allusions, fascists marching down the streets of Disneyland questioning or recruiting children would be extremely uncomfortable.
So tl;dr Star Wars has always used its design and imagery in a hollow way. At least the OT had compelling characters and a good plot.