Here's a couple reasons why a 'Story Mode' would be better than 'the nerf bat'
1. Storymode option allows everyone who has progressed far enough within the game/storyline to actually experience the 'new' story content while it's 'fresh'. So as a whole community we all basically know what's up...and not just a select few.
2. Currently, with coil's 'lockout' system there are static and time commitment needs, that some players, regardless of their actual skill can't meet. At least this way, they can 'see' the content even if they can't actively do the hardest form of it/reap the rewards.
3. It cuts down on run sales/carrying and the general frustrations of carrying. Why? Because it lets raiders be raiders (focus on the hard versions) and lets the rest still try it without the need for farming and/or joining a skilled team.
4. It doesn't lessen the integrity of content simply because new content came out. Currently, turns 1-9 have been 'nerfed' meaning that ANYONE, regardless of their skill who trying them now is forced to do the 'nerfed' version. So whether you are a new team that only started playing last month, or someone who just feels like now they are ready to tackle this content at it's true challenge level, you don't have the opportunity. Which is a shame, because there was nothing wrong with passing Allagan Rot, or learning properly how to deal with Renulds etc, but now people don't even get the opportunity to TRY the old version. So it could be argued that in fact, they don't get the same experience/opportunity those who did it when it was 'new' did. The game should keep it's integrity even if the content is 'old'.
5. It doesn't effect the 'raiding' experience or special-ness...actually, it enhances it. If the current endgame content wasn't watered down with the release of a new turn, you'd have less people walking around in turn 1-9 gears/drops. Meaning those who DID have it, would actually be more special and have more bragging rights. As having that gear meant you actually learned the mechanics, and found others to play with...opposed to just waiting until things were 'nerfed' and/or being carried. (Carries could/would still happen of course, but to a lesser degree as many who are currently interested in the 'carry' aren't doing it to farm gear, but simply b/c they want to move on/see the story).
6. It lessens the 'rushed' feel this game's endgame currently has. Lets face it, if you need to go on a 3 month break/break from endgame in this game you are likely to:
-lose your static
-and miss challenging the current patch of endgame at it's 'true' challenge level.
-be considered 'less skilled' due to missing said content when you come back.
Which is all silly. This is a game that overall, is designed to be time consuming but at the same time encourages progression at your own pace. But at the most endgame level, this is simply not true. If you took a 3 month break from this game as an endgame raider, when you came back, you wouldn't be able to do turns 10+ in their current form...you'd have to do the gimped version. And you'd probably (if the challenge and not the gear is what you crave) feel slighly jiped. There is no logical reason to nerf this content just so others can now do it. If accessibilty is the true reason for the nerf, than what makes more sense is to offer an easier version of the same content in tandum with the 'normal/hard' version, and just make the rewards adjust accordingly.
And while I won't list this as 'reasons' in general why having a storymode option for the high-end raid content is a reasonable request, when it comes to Binding Coil specifically, there are several reasons why 1.0 veteran players especially would like to at least be able to see the storyline. As it is the key wrap-up tie in to the 1.0 story....ironically a storyline that at least in 1.0 WAS very casual oriented as it was the main storyline. So you have a bunch of players wondering about Dalamund, Lou, Bahamut and co....who were super-duper invested in that storyline, but who might not have actually done any of the 1.0 'raiding' as they were not raiders and the original storyline didn't require a raid team now kinda left on the sidelines. Which to be fair, is unlikely to happen with the Expansion's high-end content as that storyline will be brand new and not likely tied to the fall of Dalamund, but still....in this case, part of the reason people are wishing coil had a more accessible version is because they really, really, really are interested in finishing their 1.0 story (which should be fair....it's a 5 year old story arc at this point).