A Mt. Rushmore is in part built on fame, and the way radio has gone for a while, it eliminates a lot of people from the past couple decades. Despite that, in my honest opinion, I'd be inclined to find a spot for Sam Lit. Although I'm far from an expert on internet radio, and barely above that on commercial radio (dedicated listener back in the day, modest several year career behind the mike), it seems to me that his close work with his dad and off the air to transitioning to his HyLitRadio.com project at a minimum bears consideration.
To be honest, and not at all offensive, if Howard Eskin is worth a nomination (we're talking Mt. Rushmore, not influential), I feel Sam is a worthy nomination although Sam's credentials stand on their own, it's not a mere substitution.
I agree with those supporting the Blavat nomination.
Harry Kalas is probably worth consideration as well.