I wonder how much of this is physiological and how much is mental. I can't help but think you'd need some sort of color blindness for taste to genuinely not notice any difference between scallion pancakes. But perhaps my friend was exaggerating.
My theory is that taste is one quality that separates the academics from the business people. Academia doesn't necessitate a lot of taste. If you have it, great. If you don't have it, no big deal. On the other hand, stuff such as product design, user interfaces, even software engineering, requires taste. You need to understand what makes a good piece of software or a good product. One could argue that Steve Jobs was a product supertaster. He was finely attuned to stuff that the average user (or the average HN reader) would not see. As PG notes, taste is being attuned to the collective unconsciousness, to a collective aesthetic. If you can tap into that, you can attract customers.