I think many here really underestimate JJ Abrams. Personal tastes aside, he put Star Wars back on the map in a way not even Lucas was able to do with his PT. He deliberately set out to create a story of a NEW set of characters in a familiar setting.
All Star Wars films up till TFA heavily relied on the same set of familiar faces: Anakin Skywalker/Darth Vader, Obi-Wan Kenobi, Yoda, Palpatine, R2-D2, C-3PO, etc. TFA was the first Star Wars film not to feature any of these characters for the first third of the film, and by the time Han and Chewie boarded the Millenium Falcon, although a welcome sight, I didn’t really miss any of these iconic characters. TFA has been criticized for being to derivative for sure, but most viewers agree they really wanted to see where these new characters are going, and I think that is a big achievement in a franchise that has been defined by the same familiar faces for the past four decades.

As far as I’m concerned JJ did have a plan for TFA, and given those parameters it worked out very well both critically and financially. I trust he will come up with a plan for episode IX.