I've come to expect the overall difficulty will decrease as the next coil season begins, which I'm ok with if it meant that more people would join the top-tier raiding communities. For example ,on coeurl server we have a fairly limited raiding community (8-10 groups or so clear T9 weekly) but a lot of mainstream/casual players. We are in short supply of decent people that know how to play optimally as is. If decreasing coil difficulty meant, that this end-game community would expand by giving people clears and giving them interest to continue downing end-game, I would better accept changes.
However, the irony is that this doesn't happen. By lowering the difficulty, people stay bad at their class, because they never learn from the content that teaches them to play optimally. I'm perfectly fine with something like Echo, but mechanics nerf is just something that's making the overall player base worse down the road. Many a MMOs have followed this trend, and the end-game community shrinks to the point where the content itself starts becoming fairly easy from release.
If your argument is well we want to experience the story, I'd tell you wait for Coil Story Mode then, which has been announced. If you then told me why I would have to wait, then I would tell you, you haven't downed it yet so you shouldn't be able to experience it yet. It's something akin to watching a movie. If you don't pay your ticket, you shouldn't automatically be able to see the ending of the movie.
People who are in favor of a difficulty decrease, are usually part of the community that:
A) Suffers from forming a competent static full of their casual players on their server who generally tend to be bad.
B) Apparently no time to work at the end-game, but they want the gear/story (handouts)
C) Some people who apparently downed the content already, and still support nerfs.
Option A tends to be the more common element for this game. What's sad about this most, is that those same people who claim it's hard to form statics with decent people, or have trouble finding that good SCH or decent PLD inadvertently paint their own environment by asking for content to be nerfed thus giving (easy passes) to players without teaching them how to perform optimally. Everyone is affected by a less skilled player base (your healers not keeping a tank alive, IN A DUNGEON; Your tank not being able to hold aggro; DPS not completing a DPS race because they don't know optimal rotations), and by far FFXIV suffers from the most unskilled player base I've seen in a MMO in recent years.
This line of thinking with always hurts your game overall. Don't care how many casuals try to deny it either, any game that doesn't have an end-game becomes boring once you cap and you lose many people (Mists of Pandora for WoW, is a perfect example for this. Hardcore mode becoming so easy, that you could down them all with more or less the same gear you already had). There has rarely been an MMO that doesn't reflect this and generally those that do otherwise, don't focus around having end-game raids to begin with (RO).
Everything in this game dries up quickly.
Crafting/Gathering, Story Mode, Weekly Capping, Beast-Man Tribes. I've personally had many people I know quit because they've already did the song and dance of those 5 things alone and have mastered it. Most of the people still logging on this late into a patch, or before the next big patch tend to be your end-game playerbase, your role-players, or simply just weekly cappers and done.
I still think the option to solve this is making 2 or 3 levels of end-game content.
Normal -> Nothing really special, limited or nerfed versions of gear.
Hard-> Normal versions of gear/difficulty
Savage / Extreme -> Special versions of the gear (perhaps slightly higher ilvl), (Dyeable) being the most none breaking and yet rewarding. (This is huge incentive for the mainstream base to get into the end-game, overall improves the base the most over time)