I liked doing the Mythic quest the first time because I enjoyed ToAU content. If I was going to list one reason why the quest shouldn't be nerfed, it's because the entirety of the quest is so varied and enjoyable. Basically:
* Making a relic is a grind because it's 99.5% just farming currency/gil and 0.5% walking to a goblin.
* Making an empyrean is a grind because it's 20% farming R/Ex items and 80% farming plates/rift items/gil.
* Making a mythic is fun because it's 50% doing quests, Einherjar, etc. and 50% farming Alexandrite/gil.

Mythics are monumentally more effort, but if you find doing quests, Einherjar, etc. fun then it feels less like "work" and more like you're playing an enjoyable game. Of the 4 level 99 weapons I own, my mythic was by far the most fun to make and felt like the largest accomplishment when it was done. That said, I have plenty of gil and no desire to make a second.