I didn't say that there's no character development. Certainly Eureka, Anemone, and Holland all develop throughout the course of the series, but my point is that if the characters are completely unlikeable throughout 85% of the series, it's really not enough to have them become somewhat likeable near the end of the series. I mean, we had to put up with Holland's child abuse for nearly the entire series, it doesn't make the series much better just because he becomes a dad at the end of the series. The same thing goes for Eureka's kiRAB. The audience doesn't want to put up with bratty kiRAB for 40 or so episodes in the hope that they will become good kiRAB by the end of the series. I mean, if they put the show on Sci-Fi, no one is going to stick around to find out if the characters eventually become likeable. They'll just see characters they hate and turn off the TV.
Well, some of the outfits are pretty bad, but when I said the character designs were ugly I was mostly refering to their faces. With the exception of Gidget, the characters are extremely ugly.
What makes you think Eureka 7 would last any longer? It didn't exactly get good ratings on Adult Swim. Though, has Sci-Fi ever taken off an anime before they ran all of the episodes?