“I don’t understand our customer. They want us to make the interface like that. But that’s far from optimal design.”
“I guess they have some reasons to do it like that.”
“It’s completely unintuitive that way. Look you have to choose from several hundreds of options from drop-down until you can go further. They said they want it exactly the same like in the legacy system.”
“Um… As far as I know their end-users aren’t very fluent with using a computer. Maybe they followed exactly the same scenario for years by now and it would be hard to retrain them, even if the new one is better. I guess, that can be why the customer doesn’t want any changes here.”
“You know, that can be a reason. I haven’t considered it that way.”
Look broader. Accept you can be mistaken. Trust in knowledge of your customer. Customer is (almost) always right.