I had always worked under the assumption that, even then, “Consumer News and Business Channel” was a backronym - ie it was chosen to fit the initials, not the other way around!
Got it in one! CNBC was originally a low budget channel known as 'Tempo'. NBC attempted to buy it with the long-term view of pitching it as a business channel, but it's attempts failed, so it ultimately 'went into partnership' with Cablevision, which was really just an unfriendly takeover. That combined with the failure of the established leader of the time - FNN - got us where we are today.