You Know Where They Can Put Those Thumbs?

Why are both Roger Ebert and Disney-ABC TV claiming that the other party is guilty of withholding the signature "thumbs up - thumbs down" bit from that TV show Roger's been too medically impaired to appear on for the last year? It's a contract negotiation ploy, of course. But if it were me, I'd be taking credit for doing away with the stupid digits.
Yes, I understand that the thumb designations Ebert and the late Gene Siskel borrowed from ancient Latin monarchs decades ago (and, apparently, copyrighted) are a marketing marvel. It's how the most famous movie critics in America, and whatever the hell Richard Roeper is now, made themselves distinctive, and up thumbs have been golden promotional, um, shorthand for movie publicists ever since.
But as much as Siskel and Ebert's televised discussions taught untold viewers to think about films in more serious ways than they likely had before, the thumb thing also went a long way to bringing down consideration of movies to an elementary, will-I-like-it-or-won't-I? level. I can't tell you how many times people ask for my critical opinion, and when I try to explain it with any nuance or detail, they shake their heads and go something to the effect of "I just wanna know: thumbs up or down?" Not that I think they should be more appreciative of my carefully reasoned wisdom - I sometimes bore myself - but jeez, this is not how to talk about the richest artform mankind has yet devised.
I put the blame for this reductive situation squarely in Ebert and Siskel's hands. And yes, I acknowledge that the star ratings that go on my movie reviews hardly indicate more than a "thumbs way, way up" declaration. But they're something my bosses insist on, and not anything I would want to copyright if I could.
Speaking of which, do any living descendents of Roman emperors, or anyone else who's referenced the thumbs up or down judgment since the days of the Circus Maximus, owe Ebert royalties?