Yes, berserker01. You've created a monster.
Toad Mechanics get
Mario Kart 8 artwork before Toad himself?
Toad Mechanics for SSB4.
Just kidding.
On a more serious note, berserker01 came up with a good point; Rosalina's story is the clearest of all characters. We only know what happens to Mario and Luigi due to
Yoshi's Island(s), basically all Yoshis develop through food, and according to the
Adventures of Super Mario Bros. 3 Writers Bible, Toad was a pizza mushroom (ironically), encylopedia seller, and one of Peach's chefs
in the same period of time. Then again, that was just the show. I think.
With many characters, we're left to guess what happened to them.
But with Rosalina, it's different. See, what I like about the
Galaxy games is that, next to
Super Paper Mario (in my opinion), its story is stellar. Sure, you gotta save the prncess (in
SPACE!), but you also have a substory, a plot B: Rosalina's Storybook. In it, you learn about her youth, how she even got up in the great beyond, etc. There are a lot of parts still left unclear (Is she ever going to die? What happened to the rest of her family?), but for the most part, it covers her whole life up until that point. And, hey, why not have some sad music to make you cry when you find out Rosalina's mother died?
Maybe Sakurai (sorry if I murdered his name) realized this. If you look at Mario characters, you don't think much like, "Oh, it's Mario. It's Luigi." But as for me, when I hear about Rosalina, I think, "Oh, the girl who went up in space so she could find a Luma's mother." It's things like these that make the game a little better, and honestly, I'm sure many people here know about Nintendo doing a bunch of little things to make their games better.
That's not to say I don't want Toad. Of course I do; he's my favorite. But I have to admit, Nintendo's really weird with his importance; he's playable in
3D World, which, as I said earlier, is like the Wii U's
Galaxy, but in other games like
Mario Tennis Open, he's not in (even, as sad as it is, Boo's a playble character.) I don't know where Nintendo stands on Toad, but I guess all we can do is hope.