Once you see that an answer is not serving its question properly anymore, it should be tossed away. It's just their natural life cycle.
They usually kick and scream, raising one hell of a ruckus when we ask them to leave. Especially when they have been with us for a long time.
You see, too many actions have been based on those answers. Too much work and energy invested on them. They feel so important, so full of themselves. They will answer to no one. Not even to their initial question!
The hardest thing about customer interviews is knowing where to dig. An effective interview is more like a friendly interrogation. We don’t want to learn what customers think about the product, or what they like or dislike — we want to know what happened and how they chose... To get those answers we can’t just ask surface questions, we have to keep digging back behind the answers to find out what really happened.
Fascinatingly, one of the other big complaints people had about agile is no iteration. I don't understand how being in an agile environment makes people less iterative, but somehow that seems to be the case. And I think it's because people misunderstand and think that agile is just about putting features out faster, and not about the important part, which is getting something in front of users faster so that you can get feedback on it and make it better.
People are afraid to let design have time to actually figure out the right thing to make, because "whatever will the engineers do?" – fuck you, there's plenty for the engineers to do. Go fix some technical debt. Go fix those 700 bugs that you de-prioritized or marked as won't fix because you're an asshole.
I'm sorry, I love engineers. I don't know why I'm yelling at them. But you know, there's plenty for the engineers to do. There's all sorts of cleanup. They can work on dev-ops stuff! They can work on their build process! Make it faster! I'm not worried about keeping the engineers busy. If you think that the only thing that engineers can do is build yet another stupid feature that nobody is going to use, then you're a garbage designer and you should quit.