The purpose of stats is twofold: to measure past performance and and to predict future performance. When people quote BABIP, the aren’t trying to “excuse”’poor past performance, they are trying to determine if that past performance is indicative of future performance.
To the people that roll their eyes at mention of Harper’s BABIP, do you believe Bryce’s true talent level is a .230 batting average? Sure, he hasn’t performed at a high level, but over the long run players always regress to their true talent level. All these extra stats are just an attempt to determine the true talent level.