as much as viewers loved Cosby as Cliff Huxtable, they have already rejected him twice in post-"Cosby Show" flops like the syndicated game show "You Bet Your Life" and the NBC series "The Cosby Mysteries." And if you knew that viewers loved Cosby as the head of a harmonious, proudly upscale, kid-filled household, why would you give them Cosby (in CBS's new "Cosby") as a downscale, grumpy, retired airport worker? (He'd better have lots of grandchildren, because Cosby without adorable little kids to steal scenes from is like Jell-O without the wiggle.) As for Danson, who stars with wife Mary Steenburgen in CBS's already troubled newspaper sitcom "Ink," and Perlman, who stars in the CBS sitcom "Pearl," the hard fact is this: No member of the "Cheers" cast has ever had a post-"Cheers" hit in which they didn't play their old "Cheers" character. But, like I said, I'm no network executive.

It all comes down to context. The '80s were a time of consensus (on the surface anyway). As if hypnotized by USA Today's use of the folksy "us" and "we," Americans followed the herd from one collective feeding frenzy to the next: If everybody else thinks Ronald Reagan and Michael Jackson's "Thriller" and "The Cosby Show" are swell, well, who am I to disagree?

America is a lot more fragmented today than it was a decade ago. Consensus can't be reached on even the simplest propositions -- like, say, all people are created equal, or, it's generally not a good idea to withhold income taxes. The country is torn along seams of race, class, religion, gender, generation. And the TV landscape, reshaped by deregulation and many laws and judgments favorable to the communications industry, reflects all this. Just 10 years ago, the networks knew from "The Cosby Show" the value of black performers and audiences; now, African-Americans are apparently not worth the Big Three's time. It's bittersweet indeed that even as Cosby is being called upon to save a major network, the opportunities he created for black programming have dried up -- "Cosby" (premiering Monday, September 16) is the only new show on ABC, CBS or NBC with a black star.

Meanwhile, the mini-networks UPN and WB have prime-time sitcom lineups featuring virtually nothing but African-American stars. Former major network stars like Malcolm-Jamal Warner (Theo on "The Cosby Show"), James Avery ("Fresh Prince"), Sherman Hemsley ("The Jeffersons") and Jamie Foxx ("In Living Color") all have new shows on UPN or WB this season, joining LL Cool J's "In the House," which was picked up by UPN after NBC cancelled it, and WB's "The Steve Harvey Show," an ABC castoff. The Big Three have pushed black viewers to the fringes. And it's coming back to haunt them: Fox's "Martin" and "New York Undercover" and UPN's "Moesha," which all feature black stars, are strong competition in their time slots in urban markets.

The networks would rather merrily transport us back in time than face up to the future -- or even to the present. And that chronic lack of vision is coming back to haunt them, too. It takes the Big Three way too long to recognize and respond to hip, off-mainstream trends and when they do, the results are almost always painful. NBC has a big new space aliens-among-us series this season called "Dark Skies" (premiering Saturday, September 21) -- only a mere three years after "The X-Files" broke wide open. Meanwhile, UPN is already on its second "X-Files"-inspired paranoia-fest (the first was the late, great "Nowhere Man"), the suspenseful and witty "Burning Zone" (Tuesdays, check local listings) about a "bio-crisis" team tracking killer viruses the government doesn't want us to know about. Look at some of the most popular syndicated and emerging network prime-time shows -- "Star Trek: Voyager," "Babylon 5," "Hercules." These are the sort of fun, imaginative and just plain different shows that the networks either always get wrong ("American Gothic") or have no idea what to do with when they get it right ("Twin Peaks").

Cosby, shmosby. Give me "Xena."