Out of interest, why? I find infinite scroll a pareto improvement (an improvement with no downsides)
The other thing that's annoying me is the overriding of cursor keys, making each scrolling step much larger than it would normally be. Yes, it might be more logical for a keypress to step to the next result, but that's not how the cursor keys are expected to behave in the browser, so it's jarring.
I get your meaning but it's kind of a funny phrase to mean "no downsides to this one agent, me"
A more human reason is that personally, I like to portion out and chunk off parts as no longer requiring my attention. I read a page and move on, clear the mental cache and start again. Infinite scrolls can mess with my focus.
This is a common problem with infinite scroll websites, not just Google of course.