It’s very attractive to only focus on one metric when managing your company. It makes all subsequent decisions easier.
There’s only one drawback — focusing on one thing makes it easy to sacrifice long term vision for short term gain.
Give a young analyst one goal — “increase conversion rates” and they’ll slash prices. Conversion rates may go up but your profits will plummet.
You’ve optimized for the wrong thing.
Even chasing profit can cause short sightedness. (Dell made more profit per laptop in the 2000s because they used plastic parts, cheaper trackpads, and took bloatware royalties). Apple ate their lunch.
Focusing on one thing is easy. But easy doesn’t make it right.