Why does everything have to be metrics-driven today? My creative efforts are the things I least want to subject to metrics and tracking.
Metrics help me to focus, improve my results, stay motivated. They turn sometimes difficult and confusing process into a fun game.
Like if you're writing a long novel, or trying to blog regularly - seeing a measurable, tangible progress is extremely helpful.
That's not for everyone of course, not all people need this, but some people like it.