It's repeated because so few people actually talk to customers and meaningfully listen to them… But you're right, it has become overused.
An interesting counterpoint to "listen to your customers" is The Innovator's Dilemma, which details how increasing profit and producing a better product for your customers can sometimes make a company vulnerable to disruption.
An interesting counterpoint to "listen to your customers" is The Innovator's Dilemma, which details how increasing profit and producing a better product for your customers can sometimes make a company vulnerable to disruption.