What you described can just as easily be done on-site. Remote work merely lets these people actually do something they might enjoy instead of sitting in a chair and pretending to work for 8 hours. I’ve met people likely this and they’d rather pretend to be busy than actually do something.
I think the point was that many on-site employees get their work done just fine, but spend half of their in-office hours goofing off on Facebook or reading HN or whatever. So in principle that "wasted" time (assuming it is indeed a waste) could be put to use for a different company, with double the compensation. Obviously there are severe logistical issues if you're on-site!
