It's hard to tell if it's SE's or the players fault.
Final Fantasy games have started to follow the recent trend of working in real life problems, showing more diversity, etc.
While some games really get a lot better because of it, it won't work for all, and I get the feeling FF is one of those games whose atmosphere is hurt by it.
For example, FF XIII: We got a black guy to fullfill the quota, a boy who is a sissy and always relies on some girl so we have our non-mysoginistic quota, and so on. Not forgetting about all the discrimination stuff and everything else they tried to put into the game. Now I do realize some people liked it, but to me it all felt so hollow with all the preaching on what is bad so "be good kids and think of it next time you beat up the neighbour's kid".
For me, FF I-VII were the best parts and starting with FF VIII, it lost it's magic (although I enjoyed FF XII Revenant Wings).
The thing I love about FF XIV so much is how it recaptures the magical feeling of the older titles

I know there will be many who disagree with me, but that's just how I feel about it.
Something else you have to take a look at is ourselves.
Like you already said - we've grown up. It's way harder to give a grown-up person the same kind of magical feeling you could give to a child or teenager. The reason we still feel it in the titles we've played as kids is because our memories give it a magical feeling. It's not something controlable.
So I'm not sure who really is to blame for the loss of "magic" in Final Fantasy, but I think they are doing a really great job with FFXIV in recapturing it.