They are not renting it out to 'someone' they are renting it out to a business. Everyone could do this if they have the minimum amount needed, otherwise buy more Steem or simply blog and comment.
It all depends on the reason the SP would be used for a business: the more it has, the more money it makes.
They cannot re-rent out delegated SP, it is locked to one account at a time until canceled.
Are you threatening me!?