I honestly dont get where the "I want to play the guy who doesnt do anything useful at all in combat" comes from. I must not be reading the right books, or watching the right movies. Or what ever kind of media you get these kind of things from.
Oh, they're there. They just may not stick in your mind very much.
As one example: the movie, The Fifth Element. Chris Tuckers' character, Ruby Rhod. Pretty useless in combat, and when the guns start firing, he squeals and hides under tables and stuff. But Tucker seems to have a ball playing him.
As another example: most Hobbits in Tolkien. They aren't there for their ability to skewer orcs.
There are others, and I could continue, but I think the point is made that such characters do exist in fiction and media.