OT had no coherent plan either. Did you really think they knew Leia was Luke's sister when they had her kiss him? They made it up as they went along. All movie franchises do, unless it's based on a book series.
This is legitimate point, but Lucas wrote those films before the power and appeal of story-arcs was really established by 1990's TV writers. Also the artists surrounding him represented an unprecedented outburst of creativity that carries you through the films' obvious weaknesses. He also did a good job at world building, dialogue, and character development, on the first two films, when his first wife, Gary Kurtz, and others were on board as restraints/alternative creative visions.
JJ Abrams can show flashes of creative brilliance and competent writing, like early Lost, his contributions to Fringe, and the first Trek film. He's blindingly arrogant though and TFA is a lazy, unimaginative reboot of ANH.
With all the Jedi-Sith mythos created in the EU, the alternative ideas for sequels, etc., Abrams and Johnson have squandered a wealth of ideas to borrow from (the way MCU writers do to great effect). They also don't have to do heavy lifting like coming up the basic concepts of Stormtroopers, X-Wings, TIE Fighter, Imperial Walkers, Star Destrpyers, etc. The designs are all derivative now, which frees a massive amount of creative energy. That should have made them focus on compelling, well-conceived story arcs with rich character development. Instead they gave us making-it-up-as-we-go, with dead ends and weak characters like of Snoke, Phasma, Poe, and Rey.
