Provided they stay up to date on security updates, that's a good move. vBulletin isn't free, but it's an investment DU should have made a decade and more ago.
What I can't understand is freerepublic, with their Rube Goldberg set-up that breaks down much of the time.
I suspect Jim Robinson does it simply so his kid has a job working for him, rather than working out in the real world.
He should fire his kid, compelling him to get a real job, and get whatever it is we use here, which appears to require (from what I can see) minimal or no maintenance.