You would be happy to live here in my town where the faster internet connection possible is 700kbps and you have plenty of time to click on footers of pages while the infinite scroll is loading.

There's a link to the footer, and the footer links are in a fixed footer that is always visible. Not super-pretty but I think infinite scroll just means no footer.

On Facebook there is a footer, and seemingly no way to get to it unless you find a short enough page or manage to get to it faster than the infinite scroll can load.

All of the links in the footer are also at the bottom of the right-hand main column

Thank you for pointing that out. I think that area might have been a blind-spot for me. (immediately below the ads)

This is an implementation choice, and not the failure of infinite scrolling: you could embed the infinite scrolling inside a DIV and have a visible footer DIV underneath. Or alternatively, implement a sticky footer, or e.g. a fixed footer that appears on certain conditions.