Producing code that does what's intended. The metric is fuzzy and based on the usage of the software, not the scale of lines of code. The extent of the importance of the code itself is that I'm practice software tends not to be "one and done", so you need to be able to go back and modify it to fix bugs, add features, etc., and it turns out that's usually hard when the code is sloppy. Those needs still should stem from the sandal actual user experience though, or else we've lost the plot by treating the mechanism as the goal itself