The Oldies Aren’t Goodies to Networks : TV: Advertisers who seek the younger market seem to be dictating their philosophies on programming to a dangerous degree.

On the surface, it’s just another desperate TV strategy. And by now it’s well-known.

The idea is that networks and advertisers are courting 18-to-49-year-old viewers and turning the 50-plus audience into second-class TV citizens, with CBS the only major exception.

It’s a breathtakingly short-sighted strategy for the dying network TV system, willfully discarding large numbers of viewers just when it needs as many as it can get.

But beyond the surface idiocy, there is much more involved here and it lays bare TV’s sad state--the fact that advertisers, while always powerful, now have the highly vulnerable networks by the throat and seem to be dictating programming philosophy to a dangerous degree.

For that’s what the 18-to-49 emphasis seems to be--an acquiescence to advertiser demands, partly because of the belief that younger viewers are less fixed in their buying habits.

In TV’s early years, single advertisers, handled by their agencies, owned entire series and called the shots on programs. Some advertisers still occasionally present full broadcasts, such as the “Hallmark Hall of Fame.” But it was a great triumph when the system changed and commercials for shows were divided up among various sponsors, thus giving the networks and creators a freer hand.

In the book “Live TV,” Pat Weaver, former head of NBC and one of the medium’s true geniuses, recalled broadcasting’s earlier days:

“Networks had nothing to do with radio except as facilities. . . . After about 1934 or 1935, all of the programming was done by the agencies. They ran radio and also began all of early television, really. In my case, I consciously said it would be better if we built a television service that was not agency-run, because there you must do what the client wants, and while a lot of the public interest will be covered, they still won’t want to do a lot of things that ought to be done.”

It was the kind of thinking that set TV on a somewhat more independent course, and over the years, although advertisers still were essentially the final arbiters--the source of network income, determined by program ratings--a better balance of power evolved.

When networks controlled most of the audience in their hey-day, they had far more clout in dealing with usurpers of their territory. Weak networks and weak shows have always been subject to pressure. But if you have a “Cheers” or “Roseanne” or “Murphy Brown” or “Late Night With David Letterman,” an unhappy or pushy advertiser can always be replaced with another one standing in line, waiting and hoping to get in on a good thing.

Despite their hits, however, it is logical to assume that the endangered networks, knowing the preferred demographics, initiated much of the current programming and policy on their own, not needing to be pushed too much by the sponsors.

And the reversal of fortune by the networks--seemingly kowtowing even more than usual to advertisers--is a subtle loss of some of the independence that earlier broadcasters were able to achieve.

Would today’s networks be able to present and nurture such shows as “All in the Family” and “The Dick Van Dyke Show,” slow starters that had a wider demographic range than 18-to-49? Probably not. Would “Cheers” and “Hill Street Blues,” also slow starters, be able to hang on in the nervous, current environment of prime time? Not too likely.

You certainly can’t blame advertisers for all of TV’s ills. They seemed genuinely impressed by CBS’ ability to win the ratings race last season with more than the 18-to-49 audience, and surely would welcome original and successful thinking by the networks. But the networks are grasping at straws to avoid going down, and the 18-to-49 philosophy looks like a safe haven--at the moment, anyway.

The inherent madness of this belief is not that the “Perry Mason” movies and “In the Heat of the Night” keep drawing sizable audiences, although older--but that the networks seem to have forgotten that they had their greatest successes by getting people of all ages to watch programs together, as witness “The Cosby Show” and “I Love Lucy.”

Nowadays, of course, homes often have more than one TV set, with family members splitting off to sample the wider choice of alternatives that cable and video have brought. But series such as “Roseanne” and “Northern Exposure” show week after week that there is still nothing like network TV to pull vast numbers of viewers together.

If there is any straw for networks to grasp at, it is this one--seeking to unite viewers rather than separate, isolate and lose them.

But there is more at stake: Whoever controls the direction of network programming--and it is advertisers if the 18-to-49 philosophy is closely adhered to--also eventually, subtly controls the content, the kinds of issues and controversies to be dealt with, and the shows that are to be given a chance to grow.

Even CBS fell into this trap when it chopped “Brooklyn Bridge.” The choice of overall programming direction goes to the heart of every important matter in prime time.

And at present, programmers seem to be third in the line of decision-making, reflecting the desires of advertisers and the networks’ sales departments. ABC, which has always aimed young, and NBC, which this season jumped more prominently on the bandwagon, are now actually sending the news media ratings lists not only for total households but also for 18-to-49 viewers.

You’d think--naively, perhaps--that even a commercial business like TV would have limits on commercialism. Yet now we have infomercials; new shows--inspired by the home shopping channels--that combine entertainment and retail sales, and a whole litany of 18-to-49 knockoffs. Anything for a buck. Where are “Playhouse 90” and “Omnibus” when you need them?

It’s a jungle out there, all right. “Brooklyn Bridge” creator Gary David Goldberg says programs are “the filler between the real business, the commercials.” What’s more, with full-length program commercials, we’ll now have commercials between the commercials. But the really sad part is that the 18-to-49 network catechism is missing a great big commercial opportunity: the intelligent wooing of America’s graying, growing population, which is becoming a huge force.

There is nothing more stupid, anyway, than thinking that everyone 18-to-49, or younger or older, has the same tastes or purchasing habits. But it takes some true grit to accept that fact, disregard research and tell advertisers to take a hike when they try to run your business.

It’s called showmanship. And it’s the only thing that has ever made television work.