Customers are rarely able to express their underlying issue. They usually communicate what they think the solution is.

A good product person is able to drill down to the fundamental problem the customer really has and articulate that to engineers.

Also, good product people should be evaluating the customers problem in terms of the whole market.

After all, engineering is a limited resource. So you need to solve the problems that exist for your target market, not just a single customer.

Of course, I’ve seen good engineers who can do this, but it takes time and effort to sift through all of the customers issues and work out which ones to solve. So product managers are focused on this to free up the good engineers to design solutions to those problems.