I basically said that they dont appeal to 100% of the playerbase 100% of the time and thats fine - and certainly not a reason to brush this request of with "not everyone wants that". They are constantly giving us new incentives to re-run old raids and dungeons, because they cant possibly release enough new content to keep us busy all the time. Allowing us to re-do quests would do excatly the same: it would create "more" content without having to actually develop that content after the initial system has been set up.
I play this game for fun and enjoyment - having to play through 50 hours of story to get to the quests I actually want to do each time I want to do them isnt fun or enjoyable.
And heck, ofc I argue for it because I want it - thats the whole point of requesting something: To let the devs know you'd like that feature and to potentially get enough other people to say "Oh yeah, that sounds cool, I'd like that too!"
I have farmed and completed 3 relics from the initial first stage in ARR to the last one in HW. Always when they were current. I've farmed both my ponies and my birds in synched parties, each time before unsyching those duties was a thing. I've gotten my PvP-rank up to 50 so I could wear certain PvP-sets, back when wearing them was tied to having a high enough rank. Believe me: I've put in plenty of effort. But your comparison doesnt hold up in this context: Once you get those nin-glamour-items you can keep them in your inventors and re-use them everytime you want. Thats why its worth putting the effort into them - once you've got them, you can keep them forever.
Those quests are the exact opposite: If I level up an alt to re-do them, I can do them once and after that I'd have to put the effort into leveling up again. Pretty much as if you'd farmed for those glamour-items for days and then you're allowed to glamour them once and after that you'd had to farm for them again.