Does the viewing public really care about Truman?

This is difficult to say. Truman's audiences are complicit in his entrapment, as Christof (a symbol of the all-powerful media), would be powerless without their attention. The public cares as long as Truman remains within the context of the reality show. They are not interested in Truman as a human being rather than a caricature of something they feel they have had a hand in creating.