I also agree. Send feedback at apple.com/feedback. Drill this into Apple.
But there needs to be an override in case the choice is conscious. I'd like to see the single "Video" selection in the Camera app expanded to two separate selections; Landscape Video and Portrait Video. And is should be smart enough to rotate accordingly when the iPhone is rotated.
FWIW, I found an app named Horizon that purports to do this. Disclosure: It's not my app, I didn't buy the app, I don't know the developer, I just got a hit on Google search on "phones that record video in landscape automatically".
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