To all "King of the Hill" watchers....?

I love the show, but I cannot stand to listen to Luann talk. Usuall I have to turn the channel. Is she retarded? Or brain dead. How come she can barely speak. She sounds like a two year old. Please explain the reason for this.

because she's supposed to be the hot Blondie with no brains.

She is supposed to be the stereotypical "dumb blond".

She's just the dumb Blondie. LOL

She's supposed to be seen as a hot annoying dumb blond

I can see where you're coming from. Her voice can definitely get annoying. But I think it fits her character. She is supposed to be a stereotypical dumb Blondie as well as an individual deprived of education due to her background (growing up semi-perished in a trailer park i believe).