I think thats the problem for me... just too cute. I can see how her and Sevens characters couldplay off of each other well... but she was just too darn cute/sweet/innocent = obnoxious character.
Plus, the whole bringing wisdom to the situation through her childlike thinking (she WAS a child after all) was a bit much to swallow. But then again i didn't like Whoopi on TNG either for a similar reason.
In fact.. .THATS ITS! Naomi is not Wesley, but Whoopi! The same character... able to be pulled in on occasion to allow the crew to step back and look at the problem through a different point of view.