1. Some people will believe any sort of nonsense that marketing people tell them (often corroborated by accompanying magazine/web articles). They are not technically minded enough to be able to tell the difference between techno-speak nonsense and physics, so they tend to believe stuff if it can be made to sound plausible to them.
2. Because for some reason they have a strong emotional desire to believe in such things, they will automatically reject any educated arguments explaining why whatever it is couldn't make a difference, the supposed differences can't be measured (or when measured are
far below the threshold of being audible) and the fact that differences are only "heard" during
sighted testing.
Surprisingly many people here, who you would think should know better, behave exactly the same way when confronted with something that sounds plausible to them but they don't fully understand. You can tell them why it's fairly easy to prove that it's bogus marketing, but it doesn't even move their needle to introduce even a tiny bit of doubt in their minds.