Point noted, but this sort of thing where a suggestion of the customer is actually useful and taken into consideration happens more often than you think/ claim to suggest because even if people are experts in domain knowledge, they can have radically different perspectives.
To be dismissive of ALL opinion is too elitist for my taking.
it is not elitist.
maybe you heard of this saying before, “idea is cheap; execution is everything”
so it is not customer’ opinion is not useful. some of them are useful, but often there is no way to execute it correctly and (even harder) properly.
idea/opinion is cheap. something that can easily execute, with tangible ROI, and the proper function to execute is priceless.