Why wasn't Ukyo a main character?!

She was a regular in the TV (and manga) series, and she too is pretty formidable in a fight, so why couldn't they have had her join Ranma and the others on their quest to save Akane from Kirin? Why did they have to only have her make a brief cameo at the beginning and then disappear? That's the only thing I really DON'T like about the first RANMA movie.

(Thankfully they corrected this screw-up by making Ukyo one of the main players in the second movie, NIHAO MY CONCUBINE. That, and the fact that Ranma spends more time in his female form in the second movie, is why I like the second movie better than this one. However I think this movie has a better end song.)