Roone Arledge wasn't doing any recreational medicine. He was responding to pressure from Howard Cosell, for Roone to widen Howard's appeal.(Let's remember, Howard had rather a high opinion of himself.) Roone hadn't been made head of the entire network yet, but he was still responsible for the sports division. The original "Saturday Night Live" was an Alan King production. Alan was an old-school Vegas comic, who got ABC's attention by producing "That's My Mama". This was a medium-size hit for a season or two, starring a pre-"Love Boat" Ted Lange. Alan wanted to make a bigger splash, and he needed a high-profile host for a weekend program patterned after a Vegas revue.
ABC was having trouble getting its' footing in this time slot; NBC was trumping them at every turn, even with Saturday's Tonight Show reruns. Neither Joey Bishop nor Dick Cavett could give them any leverage.