Presumably, Apple thinks that "the way things should work" is that the webpage author has the choice. After all, they're the one who put that CSS property into Safari. They wouldn't have done that if they thought one of the options was definitively better.

> Apple thinks that "the way things should work" is that the webpage author has the choice.

No, the way Apple thinks it should work is expressed in the defaults, the options are there if the author is trying to do something else. There are cases where it may be a good idea.

I don't see how this is one. I get Google thinks they know better (and I really do wonder what they think the benefit is), and I now avoid one of their products that I actually liked quite a bit because of it.

> The real sin is inconsistency with the rest of the web on Safari

Close, but I think it's a bit more subtle than that. AMP presents its content as a standard news article (in both function and form,) which is why scrolling should be consistent with other article-like webpages. When a site is actually a webapp, I think it's permissible to have momentum-based scrolling just to achieve parity with native apps. Perhaps I'm just being pedantic, but the real issue is that AMP's scrolling isn't consistent with a subset of other websites accessible through iOS Safari.

It's even worse than that. The search results on Google scroll with one "weight", then when you tap the AMP link and all of a sudden it scrolls differently. Keep in mind that your address bar says "google.com" the entire time - this is inconsistency within the very same site.