I read a quote that said something like, 'Character begins at the missing of the mother.' I'm sure it has to do with being independent. Still seems a bit.. murderous, don't you think? I didn't see Brave, but I heard her mom lived. Seems like an oversight on Disney's part.
I don't know if killing off the moms is Disney style per se. Killing of the mom may happen frequently in the "princess" movies, but generally speaking, the moms live in Disney movies. A few famous examples: 1. Sleeping Beauty's mom didn't die and they were reunited. 2. Simba lost his dad, not his mother. 3. The fate of Ariel's mother wasn't really discussed (I always imagined she spent her days in Triton's undersea harem) 4. The Dalmatians' returned to their mom. 5. The Aristcats returned to their mom, too. 6. Minnie Mouse must have had a living mom, as Mickey was late going to dinner at her house. 7. Poor Pinocchio didn't even get a mom 8. Dumbo was reunited with his mom. 9. Winnine the Pooh had neither mom nor dad. 10. The Mom was the only parent around in "Old Yeller". 11. "Freak Friday" would never have occurred without the mom. 12. The mom character was integral in plot of "The Parent Trap" films. 13. The much put-upon Chicha from "The Emperor's New Groove" was at home 24-7 for her children. 14. Wendy, John and Michael may have treated their mom like she was dead as a door nail..but Mrs. Darling was waiting at home with open arms once the ungrateful brats got bored with Never Land. 15. In the controversial "Song of the South", Johnny's parents only separate, and he lives with his mom until his near-death experience when dad suddenly returns and the parents are reconciled.
Read this article in The Atlantic. It discusses the topic at length. I've heard comedians make the joke for years, but this is the first time I've seen how many women died and how (including Ariel's mom apparently.) http://www.theatlantic.com/magazine/arc … ad/372270/
Actually, though it has nothing to do with moms, I was thinking about Gurren Lagann, and how Kamina's death is what drives the show forward (but only after driving the show into a suicidal depression).