This case study would be seen by some as a reason not to understand users at all. “If I asked users what they wanted, they’d say faster horses. Hurr hurr.”
In fact, like the idea of faster horses, it demonstrates how important it is to understand your users in the right way, not just pay lip service to doing so.
Badly-designed user research leads respondents to certain responses. This is often unintentional — avoiding bias is difficult.
Sometimes it’s intentional. Perhaps the survey designer has a pet idea. They might (subconsciously) skew the questions in a certain way to get the answers they want.
A classic example is asking someone if they would like a certain feature to be added to a product. The answer is almost always: “Er, yes, I suppose so.” People think they like choice, so more features sounds good. But in reality, too many features — or too much choice — leads to choice paralysis and greater frustration.
The lesson isn’t to ignore user research. But be aware of your biases. Be wary of surveys as a methodology. And don’t simply ask people what they want. Instead, understand what they do, and why they do it.