It's also super awkward to talk to someone and get a real good understanding of their experience, how they fit, what they've done, what they'd want to do.... and then find out they can't code. And this does happen. It's much nicer for all involved to do that early in the process and write it off as a formality because it's a humiliation to throw that at someone at the last minute. It's an insulting waste of time for any decent candidate, but there are always candidates who can do everything but code and you have to weed those guys out.