Sorry to be the one to say this, but there's a flaw in your premise, in that it assumes altruism is the primary motivating force in the WTS...
This is not my premise, I'm trying to argue a point with a JW relative who says that Disfellowshipping is not an outright means to control people. He says it is an unfortunate necessity that is carried out in order to accomplish their assignment from God to spread the word and live in accordance to his commandments. He says it is much like a family who has certain members of the family who continually cause the rest of the family distress and termoil and for the good of the family unit, the other members decide to cut him out of their lives until he demonstrates that he will no longer be a source of problems.
This makes as much sense as wondering why Fidel Castro arrested and executed political critics, doesn't he want them to be out in the population working in order to collect taxes from them?
I understand what you are saying but comparing the ousting of someone who is "causing trouble" from a congregation, to Castro's executions doesn't seem appropriate in this case.
To use your own comparison; McDonald's is a business first and foremost; it disciplines workers who act inappropriately - not because it wants to altruistically feed the masses (if that were the case, it would give people food for free) - but because McDonald's employees who act inappropriately negatively impact McDonald's financial bottom line, which, in turn, ultimately threatens its survival.
He agrees, the Watchtower/JW.org is a business and has to be run like one to keep it going but the congregations, where the individuals attend, isn't a buisness. The congregations and individuals are like customers or patrons of the Watchtower/ JW.org. If the Watchtower is all about money, they'd want to keep as many of their customers as possible rather than put them out. He says this proves they are more about accomplishing thier mission than they are about making money.