A change in demographic probably made them change direction. The old players from the early days have switched or the overwhelming new fan base got more say on the revenue. I just think their marketing team and vision wants to accommodate new generations of players. The recent remake and FF15 will be someone else's childhood so maybe we're going to get the same sentiment from this new generation decades from now.
Another part that brought up some changes are the creative team behind the old works. Some work for a different company now and some were replaced for younger blood vision. My first Final Fantasy was IX and then played the game version backwards until FF7. Couldn't find a physical copy of the old versions so I'm just going to have them on emulator in the future. I probably wouldn't get the same feels due to being sensitized with the new graphics but still curious about the play experience.
I like FF for the stories rather than the gameplay. And yes, FF15 story disappointed me a lot.
I remember hearing a story about when FF13 was ill received by just about everyone that the developers publicly admitted that they were focusing totally on graphics and not on really anything else about the game when they were making it. This is the wrong approach if you ask me and in your last sentence, it appears as though you agree with this sentiment.
FF13 story wise had a lot of plot holes and it goes the same for FF15. I do agree with you on how small story loop holes ruin the game as a whole. I think the whole player experience can be divided into two categories, those who are playing for the story, and those for the gameplay/challenge. What made some of the games bearable is how well the characters are written, their dialogues, and how the stories intertwine. That goes for me as playing for the story. But my friends wouldn't bother being near the game as soon as they see the retro graphics and will just stick to their cool flashy animation fight mechanics of the new age.
To be fair my opinion about the majesty of the older FF games is based a lot on my memories of it and I think that in many ways that those experiences from 20 some odd years ago are much better left in the past. I have, on occasion attempted to go back and play some of my childhood favorites only to quickly get bored - good story or not. I think one of the major reasons that I could never return to play the early FF games would be because of the RNG oriented battle encounters that would happen all the way through the game.
This has been the bane of my gameplay back then.
Anyway, the biggest factor I could think of why old games of our childhood were damn good is how our expectations weren't that high yet. Everything is a new experience and those come with emotions tied to the game experience. We got used to the magic over the years and our bars become higher each time.
Someone's childhood will be FFXV and they're going to think it's the best game in the world during their childhood days and that's fine.