Customer focus is not a marketing thing.

Every day, in every situation, we deal with customers. Sometimes it is people paying us money for a service or a product, more often it is a person we feel might be better off with a different perspective or performing a different action. Of course, calling all of them customers is reductive (and inaccurate), but the point is, you do not need to be a marketer or a sales rep to understand and appreciate the importance of customer focus.

If you want change, you need to read their minds, feel their pains, participate in their efforts, respect their ambitions, and craft your message in such a way as to converge with their world view at the right time.

All that is left is being stuck. And nobody is driven by that.