Because their stuff sounds great and is priced very low for the sound quality, you could often double the price of a Hifiman headphone and it would still be competitive. Edition XS is under half the price of the LCD-X, and it's a better headphone. And this isn't because the LCD-X is a bad headphone, either, it's a benchmark around its price. But this is how good the Hifiman value proposition is.

It's not like other companies don't have issues either, Focal and Audeze are notorious for failures. I have stuff from all of these.