When Sandisk created the Clip+, they didn't have that much concern for the SQ, if it's good enough, it's ok. Even battery life would matter more for them.
When HD created the Hifiman player, they only cared about the sound quality, and besides that, not a lot more. Apparently, there is more technology about sound quality in the player to make it sound better. You just don't understand the techniques, and you are attributing your inability to understand to something unproductive, and at the same time, derailing the thread.
I recommend listening to one before you say anything negative about the player. That curved plot itself means nothing, if you don't listen to one.