First of all, NM spawns are already in the game. I highly doubt they'd be moved into instances.
Second, I don't understand how people can hate instances so much when instances were already in FFXI.
Third, I REALLY don't understand how people can consider 24 hour spawn-camping a superior situation to being able to enjoy content any time you want.
I used to be "teh hardcore" when it came to MMOs, but that was when I was young, single and had all the time in the world to grind for extremely low drop-rate items. I don't have that kind of time anymore, and neither do the majority of people who would play FFXIV, you know, by paying money to keep it alive.
Instanced content was not created by Blizzard, and it's not going to do anything but ensure that players who have very little time can still log on and experience solid content in a reasonable amount of time.
Camping for 24 hours, waiting for a rare mob to spawn, is NOT a good way to determine whether or not a player should get to experience certain content. In fact, it's a terrible way. It's designing content for a minuscule group of players, ensuring that most players will never see it.
Instancing does not automatically transform the game into a theme-park MMO (a term I had coined for WoW years before I started seeing it on the internet, FYI). It allows players who are still gamers to enjoy content, even with a limited amount of time to play.
Why is that such a bad thing?