I think when he says leases steem he means them leasing it to other people and getting paid to lease their steem.
One example i can think of is "freedom" who was leasing to bellyrub and buildawhale, or maybe he was delegating im not sure, but his roi was huge, he was getting payments of something like 500 sbd a day from one bot and has around 7 million sp. To me he is a savvy investor but i guess some people may see it as a negative for one group of people to hold massive amounts of sp, then get paid in sbd that they convert to sp and so on so forth.