In my experience it's more like customer-facing people, sales and support, get to know the customers needs and pain points, while good technical people knows the limitations and possibilities of the systems involved. By working together the sum can be greater than the parts.

As a dev I strive to talk to sales and support for this reason. It's not seldom I can do a small change that drastically improves the user experience for one or more clients, be it existing or potential.