Massively cannot have meaning I think without a word to modify, in this case it's modifiying Multiplayer. So if that's correct then MM means a lot of people. No size of game.
In regards to XI, I think it's really silly for people to praise what XI was so much. And it's even more ridiculous for people to admire how "hard" they think the game was.
I don't think the game was hard at all. It had a very long~ leveling process combined with little to no solo capability, forcing players to not only group together, but to do so for hours and hours in order to get to cap. This isn't hard, it's a giant time sink. My personal opinion is that THAT is not good game design. Good game design in my opinion is about giving players a choice. In XI, you have very little choice. You played the game in a very linear way and that way was almost always requiring you to group for just about anything. Again, no choice is not good game design imo.
FFXIV gives you a lot of choice. So much choice that you have to make an effort and a plan you prefer for leveling. What choices can you make? Well Discipline for one is our greatest choice. We can choose very different game play styles as our main activity. Battle, Gathering and Crafting.
Picking Battle for example you have a choice. Solo or group play. And you can do that all~the way to 50 picking one or combining the two. That's a very good thing I think. Choice.
There are a number of things though that are hindering XIV such as fatigue, lack of party search and lack of story (for a FF game). The first two I think right now are playing a big role in holding back a lot of party play in this game.
Honestly, the game isn't that bad. It's the community. People are LAZY (or many cases like myself short on time) and they won't bother with making XI style parties unless they absolutely have to. Seriously, almost everyone seems to be like this. They can't be bothered to join or make a party for whatever number of reasons. They choose to solo until they face the SP hill and then they'll group up. Not because they want to, but because they feel they have to now.
XI wasn't hard and it didn't have a good community because it was hard. XI had a decent community and a higher chance of making friends through FORCED grouping. It wasn't bad for it's time but gaming has evolved tremendously and a game like XI launched now stands no chance of commercial success with so many other MMOs providing far more entertaining experiences.
I honestly believe that the gaming community has also changed since early XI. Back then, more people had significantly more patience I think and more positive thinking. They enjoyed the game for what it was and enjoyed getting to know other people in the game. Todays gaming is not like that at all. Why? I could write a book why, but I won't.
OP this game has it's issues and I question my own future in this game from time to time. There are so~ many more games out there and coming. If we're not enjoying the game right now, I see no reason why we shouldn't take a break, play a different game and come back if we want to later when they've made the proper adjustments.