The simple answer, since I love answering questions with a question to
annoy people: Why NOT? Why not make a shrine to a character I like? It's
better than wasting my time making some stupid anti-site. (Miko-sama
strongly dislikes anti or hate sites. 
) Of course, you probably want the complex answer if you're here. You
probably want to know why specifically a shrine to Kaioshin.
.........Why NOT? Just kidding. I think he's a cool character and that he's under appreciated. So what if he's not as strong as any of the Saiyajin who are running amuck? He's a deity trying to do a five deity job! It damned well can't be easy trying to watch over the whole bloody universe. Or even just one part of it. Anyways, if he hadn't been around and Majin Buu was released, things probably would have been even worse. ("That's the thing about life. It's never so bad that it can't get worse." - Paraphrased from Calvin and Hobbes.) But this shrine is mostly here because I like him, and I think he's probably more under appreciated than Mitsukake from Fushigi Yuugi is! Now for the fun part for me to write, and more boring part for you to read.
.........I'm sure some of you are going "Wait a sec. You're a fangirl of some short purple guy with pointy ears and a white mohawk? Boy are you WEIRD." .... Well, yeah, I am weird. I'm an otaku, what did you expect? Did I mention when I first became an anime fan, I was a Zelgadis fangirl? He's a blue and stony guy with pointy ears and wire-like hair. Nobody seemed to think that was strange. I suppose that's because Zelgadis has a huuuuuge fan following. Anyways, for somebody who is indeed short, Pixy Stick Purple, has pointy ears, and a white mohawk... he's cute. Yes, I just called 'god' cute. Diving further into my fangirl reasonings, I must state that I like eyes. Eyes rule. Zelgadis had nice eyes. Tasuki has NICE eyes. Hell, Tasuki has SEXY eyes
. Quatre has nice eyes. They all have every expressive eyes. I love that.
One of my biggest bones of contempt towards the DBZ art style is the eyes.
The style just does not lend itself to showing emotion the eyes, save for
ditzy happiness/humor and anger. But for some reason, Kaioshin's eyes seem
different. Or at least, more expressive than any of the popular characters.
I don't really know why I think that. I just do. Oh yes, I know 
. He dresses funny. But it works for him. Even the damned poofy shoulders.
I wouldn't wear something like that, but I do think it works for him. Just
like spandex works for Heero Yuy and Vegita. He's just so DIFFERENT
from the other characters. And before I continue to the next paragraph,
I must say, given he's been around a few million years, he probably knows
quite a lot. Probably quite good at intellectual conversation if
he actually sits down and really talks to somebody. Though that's
probably unlikely. I suppose it would be rather lonely being a) the last
of your kind, and b) being a deity of such high rank. Moving on, moving
on.
.........
I must admit... When he first showed up, he was kinda creepy with that
smile and his eyes kinda squinty. Don't get my started on how annoying
the emphasis sparkles on the Potara earrings were. (I can't even get my
big silver earrings to sparkle that much! ...At least he doesn't sparkle
as much as Hotohori. Heheheh.)
.........In conclusion, finally, this shrine is here because I think such a spiffy (yeah, spiffy) and under appreciated character like Kaioshin
deserves it! And it would be rude of me to take the title of Kaioshin no
Miko without building some sort of shrine to Kaioshin! After all, miko
translates to priestess or shrine maiden! (Besides, the other two bishounen
I adore already have PLENTY of shrines.) That's all, go to some other section
now. ~ Kaioshin no Miko