It'd be interesting to figure out (though I'm not sure how to measure it) how important each of the factors are. For example, one factor is just a marketplace/organization kind of value, the same reason eBay skims n% off every sale, or TaskRabbit takes a percentage. On the other hand, I wonder if there are more structural reasons for why his employees wouldn't be able to cut out the middle-man. For example, is there a kind of class- or race-arbitrage going on, where people are more willing to deal with him because he's "like them", whereas the cleaners come from social groups that the typical clients are more scared of contacting directly, so it's easier for them to get work if he's their public face? If so, that's not his fault (he'd just be arbitraging an existing societal imbalance, which arguably actually mitigates it), but would be interesting to know about.

Well (perhaps I misread) but it seemed that you were implying that he is getting more money than his value is worth here, and that they should instead form their own collective. My counter was that the cleaners don't need to work for this guy, they choose to, and therefore they have by definition decided that his value proposition is worthwhile.