Using a trackpad would mean I'm hunched over my laptop trying to destroy my back and neck further than I already have. Designing websites specifically for anti-ergonomic use cases is unwise.

Designing for one thing that's really good in a world of things that are average, isn't the best strategy. Reminds me of "Designed for IE6" and look where that got us.

This broke the "two finger right sweep" to return to the previous page (HN). I had to touch the back button on Safari. Felt horrible about that ...

I think that is Apple's mistake. I have to go into settings and turn the two finger pref/next pages to three, three finger spaces swipe to four just to avoid the problem you described.

And why the hell don't they enable "tab to all controls" by default?

Yes, still, I only "use" this feature by mistake.

especially because it's too easy to make it when scrolling up