Asking questions to customer is wrong when the customer wants to return something he or she has purchased. However, asking questions - as many as five times - is desirable when a customer wants to place an order. Dialogue on this fashion may help business (and customer alike) find the actual need.
For instance, a customer may think that he/she wants to build an ecommerce portal to sell online. But a Five-Why session may reveal that for the given team size, expertise and purpose, an account in Amazon or eBay will prove to be a better solution, than developing from scratch and maintaining an e-commerce portal.
We call five-why session as "active listening and need-finding". (Refer to the flowchart below). We believe that this approach is what differentiates a "design thinking" company from just another design company.