[prideout]

It sounds like the opposing arguments are: (1) if you want something to exist, you'll be biased in your observations, (2) we might simply be unaware of a bunch of Kuiper objects, and those unknown objects might be exerting their influence, and (3) we haven't actually seen P9 yet, visually, so skepticism is healthy until then.

[yamaneko]

Yes, thank you. It's been a while since I've watched the video, so calling it "opposing arguments" was a stretch. More like a healthy dose of skepticism.