Earlier quoted context omitted.
I actually think it has more to do with the increasing size and sophistication of the touchpad in Macs. There is no need for a scroll bar when you have a touchpad you can flick (likewise for magic mice).
But the touchpad won't help you visualize where on the page you are.
That said, the issues outlined in this article are glaring, and I do notice them when I switch to PC/Linux and a mouse and back. It's definitely something easy to forget, though.
The UX is designed to make most of the obviousness fade away and make the process an extension of your natural movements. Kind of like how a good band can take cues from each other without explicitly speaking or reading off of a sheet during a performance. But that doesn't help people who aren't adept professionals, or people operating under completely different circumstances.