I have friends who would be interested in coming back for the new expansion but will not because they are so far behind on the MSQ that it would take quit a grind to catch back up. I really think this is a oversight in the expansion process of this game compared to other MMORPGs. A new expansion is bringing people back because they are interested in the content of that expansion but instead they get stuck in dead ghost towns of previous content and once they finally catch up everyone is in the new expansion content is done with it.
Yes I get that FF14 has a stronger emphasis on story compared to a lot of MMORPGs. I know someone without fail will show up in this thread and make a hyperbolic statement like "well if you don't like story content you should be playing a different MMO". However, even the biggest story enthusiasts have to agree that there is a large amount of filler dialogue crap that is not memorable and doesn't serve any purpose but to waste time.
In addition, the simple reality is that some people play MMORPGs for different reasons and some are not just that crazy about story content. It will not hurt your story loving experience if someone else wants to have a more abridged version to catch up to current content.
I think either the old story content needs to have a large amount of its fat trimmed off or they need to allow people to just skip a lot of it with a summary of events.