• Comcast is looking to separate from most of its cable networks.
• However, the media titan is keeping Bravo, which makes popular reality-TV shows.
• Here's why holding onto Bravo makes sense, even though the spinoff might not work.

Comcast wasn't bluffing about unloading its steadily declining cable TV networks.

The cable giant is officially planning to spin off most of its pay-TV channels, in a move that's the latest indictment of the sad state of the traditional TV business.

Notably, Comcast's NBCUniversal isn't biding all of its cable networks adieu, however. It's hanging onto Bravo, a purveyor of reality-TV shows like the "Real Housewives" series and "Vanderpump Rules."

The logic behind that decision is simple: Bravo's shows are inexpensive and popular, and they perform very well on Peacock, its budding streaming service.

In the deal, Comcast is holding onto Peacock, as well as its broadcast network, NBC. Those platforms are how Comcast distributes its all-important NFL rights, so they were never on the chopping block.

Though it may surprise some, Comcast has determined that Bravo is also too valuable to let go. Ten of the 50 most in-demand TV shows on Peacock this year are from Bravo, noted Brandon Katz, the senior entertainment industry strategist at data firm Parrot Analytics. Parrot's demand metric is based on third-party data, including search results, social-media content, and ratings sites.

"Bravo has a real brand identity that holds value to consumers as opposed to Syfy and USA Network, which have largely pulled back from scripted programming in recent years and are not as recognizable and resonant," Katz wrote, referencing two networks that Comcast is planning to spin off.

Bravo has also served as an anchor for Peacock's expansion into reality-TV originals, which has produced Bravo-style hits like "Love Island USA" and "The Traitors."

Ratings giant Nielsen found this summer that the sixth season of "Love Island USA" was the most-watched reality TV series among streaming originals, as it racked up over a billion minutes viewed and registered in the top-10 rankings for four straight weeks following its debut.

Without Bravo content, Peacock's reality-TV strategy would be left with a huge hole.

"Comcast likely views Bravo as an important piece of its Peacock strategy, with content that is too difficult to separate from the cable network without destroying any value the network might have," wrote Michael Hodel, a communication services analyst at Morningstar.

Why Comcast's spinoff might not pay off

The other reason why Bravo could have been a keeper is that it still generates cash that can help Comcast pay for the NBA broadcast rights it won over the summer.

"Given the cost-cutting that will likely be required to ameliorate the incoming expenses of NBCU's rich NBA deal, keeping that money-making asset in-house makes sense even if it's shrinking year-over-year," Katz wrote.

Still, Comcast's other cable channels likely turned a profit as well. That, plus the fact that those networks could be weaker on their own, has left some analysts stumped as to why this spinoff happened at all — other than to make investors happy.

Wall Street generally hates declining businesses, like the pay-TV networks that Comcast has been saddled with.

"Comcast will now have a cleaner and clearer growth story," analyst Craig Moffett of MoffettNathanson wrote to BI.

However, Moffett said that the spun-off networks likely make more sense with Comcast than on their own. Analyst Rich Greenfield of Lightshed Partners had made a similar point a few weeks ago.

"It will be challenging to separate NBC from the cable nets, especially for carriage negotiations," Moffett wrote.

Brian Wieser, a media and advertising analyst for Madison and Wall, struck a similar tone.

"Unless Comcast has a vision for what it would do with the capital to build up its remaining media business or how it will cause a merger of the business with another company's cable networks, the transaction would be dis-synergistic," Wieser wrote.

Whatever the fate of the spinoff, Comcast clearly sees the value of Bravo's scripted content, compared to the more challenged TV news business. Investors will ultimately judge whether the spinoff was worth it. As of midday Wednesday, they seemed unconvinced, as the company's shares were only up modestly hours after the news broke.