The cultural angle is covered near the end of the video (around 11 minutes). Apparently there is some evidence northern Israelites were still eating pork and the rules became a way to bind everyone together culturally, though like all other reasons there's no hard evidence.
When it comes to eating dog, the prohibition feels nearly as strong as if it came from God. It would take only a little nudge for somebody's existing dietary preferences to become scripture.
That preference might have had some other kind of more immediate necessity as well, but a lot of such cultural dictates are either arbitrary or become arbitrary as circumstances change. That just makes the cultural marker even more imperative. It would be easy to avoid pigs, say, if they were actually bad for you. Avoiding them even when everybody else is consuming them successfully shows a real determination.