Whenever someone brings up FFXI people immediately thinks they want a clone of FFXI and that "Bawww FFXIV is supposed to be different go back to XI!!!!1".

The thing is, while FFXIV is supposed to be different, it almost died a month after released because it was trying to be different for the sake of being different. Before I go into examples here's the basic systems of FFXI for those that don't know:

-Search system
e.g /sea jennestia will bring up my character name, location and a search comment if I set it and also allow you to invite if lfg and in same region/send a tell/friend request.

The search system of FFXI was extremely basic though rarely even used in MMOs as they typically used a different type of search, however they also worked very fluidly.

-Linkshell Management
e.g kick/promote/set linkshell message etc. Basic foundation system.

-Client side interface.
Self Explanatory.

That's just a few things foundation wise that XIV could have benefited from, yet people go into a hissy fit simply because FFXI had it, which is basically the next "Why you gotta bring up WoW?" Since it's apparently too much to expect SE to remember the basics after 10 years from another Final Fantasy MMO they've done.

XIV's foundation lays as follows:

-Serverside interface
All this does is hinder the game's foundation.

-Linkshell management
Very Limited and will eventually expand.

-Recruit system/"new lfg system"
Some say it's better, but it's still restrictive in implementation, still no exact "Look at me I'm looking for a party!" like with XI yet.

Basically, they went with the route of a serverside interface which no other MMO has more than likely to try to curb RMT, however it also hinders progression of basic features.

Now, people say FFXIV is supposed to be a different game and that the only similarties to FFXI should end at the races, that's cool, however here are my examples of what it means to be "different":

Rift

It's a blatant WoW clone, however it's main feature, Rifts, are something different from WoW but Rift also built off of the foundation WoW laid.

Eden Eternal

A fairly newish MMORPG and also one of the few that allows you to job change at will on the same character, it's actually fairly close to how FFXI is, but it's layout and progression is, you guessed it, built on the foundation of other MMOs, e.g Quest based progression, tons of management tools etc.

Iris

Similar to Eden Eternal, but also different in it's own way. However yet again, built on the foundation already laid by MMOs.

Final Fantasy XIV

Threw out everything FFXI laid and pretty much any other MMO foundation wise, also released unfinished. The only difference was the ability to cross class abilities which isn't even unique anymore as Eden Eternal allows as such (and does it a bit better actually in some instances).

The main thing about "being different" is taking what works and building off of it, not throwing it out and reinventing the wheel as people call it. So every time it gets brought up that FFXIV is "supposed to be a different game", that's no excuse for the bad design decisions or the fact the game almost fell into a void a month after release and they later had to scramble to save it. Being different generally means building off of what works and taking your own spin to it. Another good example is Sci-fi, there's Star Wars and Star Trek, both have similarities but both are also very different however both are of the same genre.