I disagree. I think a lot of classic is better than retail. One of my biggest complaints in retail is that nothing matters and nothing outside of mythic raiding or dungeons matter. Classic, despite being grueling at times (especially when solo leveling a warrior) feels like I really am progressing my character. I do however wish we had quality of life changes.
What harm would a barbershop have? What harm would the dungeon journal have? What harm would achievements have? What harm would the option to have retail graphics and animations and sound have? So on and so forth.
So many of these quality of life changes have 0 effect on game play.