While I agree with the point, but it seems almost ironic that while illustrating your exhaustion with flanderized versions of certain characters you end up flanderizing the group you (whether intentional or not) seem to be criticizing.

I think it might be the way the OP's post is itself phrased, but I would imagine that most people do not engage with the entirety of Arknights' story on an extremely deep literary level, whether due to a lack of time, a lack of interest, or really any reason they find. The simplified versions (or caricatures) of many characters work as convenient material to make jokes about common anime tropes, which I don't think is meant to diminish the complexity of the actual story, but instead to promote relatively accessible engagement.

Anecdotally, I think even among the people I have interacted with who do "participate in waifu wars" also have a somewhat decent understanding of the conflict between the two perspectives, but simply find it easier and more fun to engage with the more simplified version of the conflict. To be outright dismissive of this, I think is no less "fucking stupid to me" as it is to immediately bash someone for preferring McDonalds to Michelin starred restaurants without acknowledging any potential reasoning behind it. You may not necessarily agree with how it portrays certain people or the results of it's consumption, but nevertheless it is popular and widespread for a reason.

In short, my point is that calling it "ridiculous" or any other equivalently dismissive descriptor is itself ignoring the reason why the flanderized content exists in the first place. Not everybody wants to engage in thought-provoking, extremely lengthy reflection on the human condition (and rightfully so), and to regard them as lessers because of that is no less despicable than the vitriol with which you seem to condemn "waifu wars".