Why do we want to distortions?

Thank you for your comments.  but what I am trying to understand is if the original recording is with  euphonic distortions that are deemed as positive then don't we want the most transparent system to hear the original   and   How does tube  euphonic distortions add a stage to the sound?

@atmasphere   Thank you for the clear and detailed response. You provided me a level of education in audio that I never thought would be obtained on a forum.