Why did Pixar remake the TV show "Herman's Head"?

Rating: 6/10 (6 February 2016)

If you remember the early 90s TV show, Herman's Head, you probably know about how its impact on TV was more how its cast powered The Simpsons. And if you remember the premise at all, you'd remember how silly an idea it was.
Which makes it shocking that Pixar decided to essentially turn it into an animated movie about an 11-year-old girl disaffected by a family move.
Minor character spoilers ahead - but nothing you wouldn't see in a movie review.
The execution is generally Pixar quality. But there are some major story design flaws. Why is Joy the dominant emotion and the rest are just problems? They tried to make peace with it through Sadness later on, but it still came off as a forced attempt to validate the value of any of her other emotions.
The rest is very much an Alice in Wonderland/Wizard of Oz story, which is great for kids. Good humor. Some cute staging of scenes. But the 11-year-old played by Amy Poehlers voice is very one-dimensional in her transformation.
There are enough Pixar employees who capture San Francisco quite well, but this might have worked better as a kid moving to Minnesota.