I think this huge point of contention with FFXIV—why you see veterans and new players having completely different attitudes about the game so often—really just boils down to the fact that new players experience everything in one go, but longtime players have experienced content bit by bit as its released. I think this is a crucial difference that's frequently overlooked by the community and makes for a much different impression of the game.
If you're like me and have been playing since the 1.0 days or ARR's launch then you're probably a lot more fond of the game overall having seen its growth firsthand. For me, half of the fun of MMOs (especially FFXIV with its strong emphasis on story) is anticipation and speculation. There's a lot of excitement in seeing where things go and having that time in between patches to really digest the content, discuss, and speculate. What's going to happen in the next patch? What primal would make sense here? Wouldn't it be cool if they brought in these bosses from this other game? New players completely lose that meta experience playing it all in one go, and I do think that's unfortunate. Burning through the game all at once seems to kill the magic a bit, but it's certainly not the case for everyone. Without being able to watch the game unfold in real time it takes a very particular mindset to appreciate things in the same way, and plenty of new players, particularly those that love JRPGs, seem to do just fine with the "slog" simply because they tend to join the game with said mindset.