Why do people call eren and yeagerists fascists?

Why do people call eren and the yeagerists fascists/nazies/psychos for wanting to genocide the rest of the world to protect paradis, when the rest of the world was actively ON THEIR WAY to genocide paradis? A lot of innocent people will die but like wtf do you want them to do? Without the full rumbling, paradis is doomed, which is what happened by the end, it got bombed by the remaining 20%- do you ever think that the alliance’s great great great grandkids were bombed because of their betrayal? Genocide is bad (no shit)- but it was a us vs them situation. Eren completing the rumbling doesn’t need to be seen as this celebrated thing, it’s tragic, it’s a cautionary tale for what happens when push comes to shove, but saying self defense makes you pro genocide is missing a lot of context of the story. Marley attacked first, Marley declared the war on them first etc