It's worth a lot to the shareholders to manipulate the stock price upwards, that's of no benefit to the customers though. Quite the contrary, choosing executives based on how well they sell equity opposed to how well they can operate a company produces worse results for the market (of goods/services, not of capital -- that's the distinction).

The shareholders are the ones paying the CEOs, though, so it sounds like they are worth it.

You're confusing the market for equity with the market for the goods and services produced by the company. The shareholders are optimizing for the former at the expense of the latter.