To expand, it makes sense in situations where the "expert" is unable to scale up any farther (lack of capital or labor come to mind) or cannot expand farther without assuming an uncomfortable amount of risk. The second possibility should set off alarm bells for small investors. (Case in point: many McDonald's franchisees struggle to break even while the McDonald's corporation rakes in a steady income.)
If someone really is "retired but wants to help people", I would expect to see the core educational content available for free (or near distribution cost) with the option to pay for one-on-one coaching/consulting services.
And since the franchisee is representing the franchise's brand they have incentive to help the franchisee succeed and only accept franchisees that are likely to succeed.
Not to mention the franchise collects commission on the franchisee's ongoing sales, not just a lump sum up front and say "you're on your own, have fun." It's quite a different ballgame altogether.