I am not disputing that at all. But it is also missing the boat.
It is like saying it is very difficult to A/B drive test two cars to pick one and therefore preference for one or the other is subjective in a negative way. Some people think speed dating is a good way to A/B test two prospects, but we do know how indicative of a good relationship that is.
There is a third possibility. Which is that A/B testing for sonic differences on the spot is a flawed methodology to pick one that would please us in the long term. So deficiencies of that methodology is itself irrelevant in that case.