People are very quick to admonish 1.0 because it failed, but people rarely address the actual reasons behind WHY it failed. A lot of the features in the old version were frankly superior to what we ended up with in ARR but were removed to simplify the gameplay experience. The OP isn't wrong when he says that a lot of the complexity from the original has been lost. Classic case of throwing the baby out with the bath water.
That's not to say 1.0 was a great game, not by a long shot. It was plagued by UI issues, great expanses of nothing-much-to-do and more lag than you can shake a modem at. There were however several things it did right, and did well.
Mobs weren't just annoying distractions, they were genuine threats on the field. I can't even remember the last time I died to an enemy outside of a dungeon or Fate in ARR, but it used to happen a whole lot more back then.
Remember elements? Fire, ice and so forth? They used to mean something too! Now it's just "spam fire, cast blizzard to regen, spam fire...". And what about the other skills in our arsenal?
Hit mob for X potency damage is all fine and dandy, but at the end of the day, there's very little to distinguish one DPS from another, just a handful of throwaway unique skills which aren't even that special in most instances.
I have a dream that one day tactics will make a comeback to Final Fantasy (see what I did there?). A day where black mages will have a suite of spells to deal with elemental resistances, instead of spamming the same two elements over and over. A day where people will say, "We really need a <insert job>" because of some unique trait which distinguishes them from the crowd, not just mere job roles.
It may be a lofty dream, but I don't think its impossible with the system we currently have. It just needs some tweaks in a positive direction.