From a marketing standpoint, TFA did what it was supposed to. Very well.
It was true that a certain portion of the fanbase felt alienated by the prequels. TFA, with the hype behind the return of the OT cast, familiar ships and sights, parallels with the OT, brought a lot of us back.
It also got people buzzing about what would happen next. Who is Rey? Who is Snoke? What happened to Luke? Why did the lightsabre and Obiwan speak to Rey? Are Poe and Finn force sensitive? Is Han dead dead? Who is Snoke?
You may hate JJ for building empty mystery boxes, but again, from a marketing perspective it worked GREAT.
Also, IF it had to be a case of "we don't have a plan, just wing it", what JJ did was the best for the situation. Open up possible paths for the story to go.
It's Rian who made ALL of them pointless and shut things off for the 3rd act.
TFA also built some cosey character relationships. Rey & Han. Poe & Finn. Rey & Kylo. Rey & Finn. I'll give credit where it's due and say it was far more fun to settle in and see these develop than anything in the Prequels. Even the MCU can't get the inter character chemistry right outside of a few exceptions (Stark & Parker, the GOTG, Thor, Loki & Hulk etc) and relies on just snarky quips too much.
That could have had a lot of potential too, but we just got Reylo instead as the remaining male leads ended up being pointless tools to illustrate stronk fuggo wimmens.
At this point its pretty much about making the best of a shit. If JJ manages to make a fun ride with some cool toys to buy, I can forgive a shit story. I don't think there's any ideal way out of this hole the Star Wars team dug themselves into.