An unstated reason is probably that the younger new wave of late-night TV hosts is not only nipping at his heels but pulling ahead of him . David Letterman , who 's retired in 2015 , has been a talk show host for 33 years . David Bianculli says it 's more than Fallon 's ` ` Tonight Show '' turn . He says many people see late - night shows as short clips or viral videos online the next day . Bianculli : Internet age has devalued Letterman 's style of monologue , hourlong interviews .
David Letterman , who 's retired in 2015 , has been a talk show host for 33 years . David Bianculli says it 's more than Fallon 's ` ` Tonight Show '' turn . He says many people see late - night shows as short clips or viral videos online the next day . Bianculli : Internet age has devalued Letterman 's style of monologue , hourlong interviews .