One of my favorite, ever, podcasts used to be the - at the time well deserved for its nomination - formerly excellent Writing Excuses. I absolutely loved it. I recommended it to teachers who taught writing, I recommended it to friends who loved analyzing books and movies. I talked it up far and wide for in breaking down the art of telling a science fiction or fantasy story, most of the material applied to the art of telling stories in general.
The founders were Dan Wells, a good if then tyro writer who wrote the excellent (and disturbingly not to my taste) I Am Not a Serial Killer, Brandon Sanderson of Mistborn, The Way of Kings, and of course finishing off Jordan's Wheel of Time series, and Howard Tayler of Schlock Mercenary. The tagline was "15 minutes long, because you're in a hurry, and we're not that smart."
The chemistry of the three was fantastic, with a mix of insights from the capable-but-new Wells, and the experienced Sanderson neatly complemented by Tayler's insights into storytelling as changed by the needs of a serialized webcomic. The time was the perfect length, forcing the show to stay focused on the topic but allowing each of the three to provide some depth in their replies.
So what happened?
Well..... Mary Robinette Kowal.
I'm going to set aside for now my intense dislike for her that I developed after learning her comments on the SFWA bulletin cover, and the "I didn't actually name Jerry Pournelle" nudge-nudge, wink-wink of wanting the "twelve rabid weasels" of SF&F to just die already.
Why did bringing in a fourth host fail?
First, simply by having the fourth host - it got shallower. With "fifteen minutes, because..." - and four main presenters, each member had less time to make a point, and the depth of the insight provided by each suffered
Second, logistics. Bringing MRK in meant that more shows were recorded at once when they had the opportunity for her to travel over, and the timeliness of the episodes suffered.
Third - little was added. Dan was both capable, but still somewhat new, so he could provide the viewpoint of the relatively new writer still working on his early stuff, bringing on new projects. Brandon teaches writing. Howard had literally years of experience in telling serialized stories via webcomics. Each brought unique insights, with the very different needs of webcomics in terms of pacing and plotting providing not only an interesting factors, but providing insight that applied to all serialized storytelling. And all were conversant, of course, with movies.
MRK brought - puppetry. And a few of her books. Yes, puppetry is different, but plays, while having unique differences from movies, are not different enough in format from movies and TV given the storytelling focus of the blog. Yes, she was competent as a wordsmith - as Jeffro's look at The Lady Astronaut of Mars showed - but she wasn't better than the previously existing hosts, and so she didn't add much as either an author or a storyteller in other media to compensate for the above issues regarding depth, etc.
Finally, she had an impact on the guests that came on. Larry Correia? Never saw him again. The people who came on had nice things to say about words, but the interviews were rarely as interesting as they used to be.
The last can be squarely laid at the feet of her pet SJW peeves and activism.
So, by the time I discovered what a miserable piece of work she was re: the weasels and chainmail bikinis, I'd long quit listening.
FWIW - the pre-Kowal episodes are still well worth listening to if you care about storytelling.