And making it soloable is going to?
That's a lot of ifs. Maybe they'd have seen the story, and never done it again cause "why bother now"? Gear isn't the only reason people do the Coils. Wait that is exactly what happened when WoW did this! Oops, you just killed the motivation a lot of people had to do raiding. Might as well give free items as well while you are at it! /s
The journey is what gives satisfaction and meaning to the reward, but the reward is the carrot on the stick. If the journey is the only thing that is important, then where is your Savage Coil clears? Oh wait, there is no carrot there, so there is no reason to do them! This is why those instances failed, not their difficulty, but a lack of reward for said trials. Putting a story mode would basically do the exact same thing. You can't build a good raid without both the trial to put some meaning behind what your getting, and the reward itself to act as that driving force to push through the content. Otherwise you either have unsatisfactory content (see dungeons) or no motivation to do said content (see savage, Ramuh pre-buff).
Yet they did wack it with a nerf bat, and did make it basically DFable. But wait! People still complain that it is "too hard". That's the thing with nerfing, there will always be someone that wants it easier until the item (or cutscene or w.e) literally drops in their lap. Coil was never suppose to be easy, it was never suppose to be equivalent to a story mission. This is why it's totally optional in both getting access to more content and not being part of the main story line. YOU don't get it, you keep talking about how there should be a story mode, when this is raiding content. SE has already given tons of easy access to the main story line for players like your friend. It used to be the case that the "main" story was told through raid content, and there was no alternative. Now it can be completed in 30min (woohoo, super easy content is sooooooooo fun) with a dungeon run peppered in. Yet I guess that's not enough, now every other piece of content has to be completed in the same 30m.
I guess it's just a race to the bottom at this point.