Last Friday night at 8 p.m., when no one in America was looking, CBS broadcast an hour-long tribute to its former anchorman, Walter Cronkite, on the occasion of his 90th birthday. It was a classic backhanded gesture by CBS, the kind that demonstrates just how callous and insensitive the network has become to its great traditions and legacies. A Friday night timeslot for a news special practically begged audiences not to watch. At the same time, the special served as a reminder of just how far CBS’s news division has fallen from its heyday, when it dominated both ratings and coverage with its all-star lineup of newsmen such as Edward R. Murrow, Eric Sevareid, Mike Wallace, Morley Safer, Harry Reasoner, Charles Kuralt, Roger Mudd — the list goes on and on.

Of course, Mr. Cronkite could not have been surprised by the insult. He has been treated as an outcast by CBS ever since March 9, 1981, the day Dan Rather replaced him as anchor and the network exiled him to a 19th-floor office in its corporate tower known as Black Rock, on West 52nd Street — as far away from Mr. Rather as it could put the correspondent who had once been known as the most trusted man in America. Mr. Rather didn’t want the long shadow of his predecessor on his version of the “CBS Evening News,” and there would be no further use for Mr. Cronkite on the network ever again — not for shuttle launches or election nights or any other substantive use of his talents. For the last quarter-century, he has languished in luxurious confines down the hall from his tormentor, Leslie Moonves, the president and chief executive of CBS, the man responsible for putting Katie Couric in his chair and for perpetuating Mr. Cronkite’s banishment from the network.

“Anchormen shouldn’t cry,” Mr. Cronkite said on the special, as he choked back tears at the memory of the Kennedy assassination, a transformative event he covered with the sort of honest, heartfelt emotion that has disappeared from today’s generation of anchors. (The last anchor to give freely of his emotions on the air was Peter Jennings, the only one ever to have approximated Mr. Cronkite’s gifts.) Mr. Cronkite’s hearing may have failed him, but not his vision: He still sees the world the way we do — angry about wars, in awe of space exploration, and cynical about government scandals. Then there’s that edge — the quirky, comical persona that made Mr. Cronkite less comforting but more trustworthy than the one-dimensional security blanket that ABC’s Charles Gibson provides. It surprised no one to learn, in the course of the special, that Mr. Cronkite still enjoys doing a mock striptease for the likes of George Clooney, or considers the Grateful Dead’s Mickey Hart a friend.

Today Mr. Cronkite serves mostly as a reminder of the reason we still obsess about the anchors of evening-news broadcasts, and still yearn for someone to take his place. As everyone knows, the ratings for evening network newscasts have precipitously declined; now the anchors fight over a severely diminished audience — and while the New York Times and Jacques Steinberg would have us care whether Mr. Gibson has more viewers than Ms. Couric, we really don’t. The news that Ms. Couric’s ratings have plummeted to 1987 levels only underscores our frustration with a network that so cynically chose Ms. Couric for her talent at attracting viewers, not her skill at covering the news.

Meanwhile, Mr. Cronkite is still robust, deep-voiced, and handsome after all these years, and conveys a concern with the world’s future that’s nowhere to be found on Ms. Couric’s frozen face, or beneath the layers of Brian Williams’s tan. Yes, Mr. Cronkite always understood that an anchor is an actor — but he always took his cues from events, not directors. He earned his credibility by not pretending to be a reporter when he wasn’t, and by being a great one when circumstances warranted, interviewing presidents and kings with equal measures of skepticism and respect. He didn’t foist ghostwritten commentaries, Couric-style, on people who wanted him to inform — not alter — their opinions. “That’s the way it is” became his catchphrase because he had the courage, the audacity to think he could deliver on that promise. You had to admire him for the sheer outrageousness of the claim, and you had to watch him because he delivered on it, most nights.

It’s no surprise that Ms. Couric has yet to coin a consistent and engaging catchphrase to end her broadcast, since it shares nothing with the grand CBS News tradition that preceded it. The beauty of the “CBS Evening News” came from the strength of its journalism — the rata-tat roll of first-rate reporters’ names and datelines at the top of the broadcast, and the presence of a former top foreign correspondent, Mr. Cronkite, behind a desk in a newsroom, not on a stage with a Hollywood composer’s score playing in the background. But after its cruel and inexplicable treatment of Mr. Cronkite for the last quarter-century, don’t expect CBS News to suddenly correct its Couric mistake. The network that has tastelessly attached the classic Murrow title “See It Now” to Ms. Couric’s broadcast has proved itself blind, yet again, to the errors of its ways.