Software developers who never have, and never will have to, use the software for real.
Yes. The customer doesn’t necessarily know what’s possible or know how to articulate what features they want. I spent one week in a position where I was using my own software for production and immediately made several simple enhancements once I had hands on experience with the expected business process.
Every programmer should go through an exercise like this at least once in a while.
OFF THE TOP ROPE!