It's about time management. Having to hunt for things is a waste of time, and those little time wasters add up to a lot of work not getting done, or a distraction that takes more time to get your brain back in gear.
I don't understand reddit_clone's specific example (are there bathrooms with 2 sinks?), but I think the article does mix ideas that are wins with others that are dubious.
Pens, chargers and AC adapters, toilet paper are cheap; running out of them is bothersome and there's a fixed overhead to retrieve them, so let's stock them and put them into the right places.
But buying and keeping 2 vacuum cleaners at home is arguably not in the same category. It only works if you assign a high enough cost to "getting up and down the stairs" or, equivalently, if the price of the cleaner plus the real estate is cheap enough for you. It's not like it will affect your "productivity", it's just a minor loss of leisure. In other words, it's a first-world-problem.
(taking the "first-world-problem" term literally: in the Third World, the problem above is "solved" by not being able to afford 2 vacuum-cleaners, or 2-story houses, if you're poor; or by hiring a maid if you're middle- or upper-class).
