invalid,
blind testing is not the answer, you might pick out a speaker in blind testing and hate it once you listen to it for a while in your room.
That's conjecture though. How often has that claim been born out?
Again, knowledge is power, and if you understand enough about speaker measurements and your room, there is some level of predictive power about the sound.
Further, speaker design has actually been advancing due to all the blind testing research that identified what type of resonances and anomalies we tend to identify as unnatural or sounding poor. More and more companies are using this information in their design, even purchase Klippel Analyser Systems (like Amir uses - Magico for instance now uses the Klippel and designs with goals similar to that targets that arose out of the scientific research.
KEF has had enormous success with their designs, especially as they also have been designing their speakers ever closer to the "best practice measurements" goals that arose from blind-research. So there really is a through-line from the studies to what many people will hear as Good Sound. It doesn't necessarily predict what any particular individual will choose, but it's clearly been helpful.
Like I said before look what blind taste tests gave us the new coke, where is that product now?
A single such instance isn't an argument against the usefulness of blind testing.
That said, I think the New Coke Problem could be raised against the type of blind tests used at, say, the Harman Kardon facilities - that is, do some speakers sound better in the shorter time period quick-switching scenario of such tests, but don't necessarily predict long time satisfaction? I think that's a possible flaw. But it might actually have been addressed, I can't remember at the moment. And it also seems fairly doubtful to me.
But to grant the proposition that people prefer X speakers in blind tests is useful does NOT mean it therefore predicts customer satisfaction per se. Clearly plenty of audiophiles have found satisfaction with a wide variety of speaker designs over the years. All sorts of confounding factors occur once you are in to the real world.