Article continues below advertisementLate-night icon David Letterman has publicly criticized CBS for its handling of fellow late-night host Stephen Colbert's departure and the decision to fill the time slot with Byron Allen's Comics Unleashed. Letterman, who hosted The Late Show for 22 years, characterized the network's move as "pure cowardice" and expressed that Colbert - whom he described as the "face of that network" - was not treated with the respect he deserved.