It's a legitimate criticism, but it's hardly a damning one.Force Awakens didn’t have to be scene for scene remake of the first one. The filmmakers could have tried to push the envelope, or at least not made it the same trite story of a poor orphan on a desert planet who blows up a round space station. But they didn’t. They opted to ape the first film, and they deserved every bit of criticism for that choice.
The Star Wars fandom is the worst fandom I have experienced, by which I mean that I don't know where there are so many fans that take the work so seriously and are so entitled about what they're getting. Navigating and satisfying expectations is a minefield, with people being bound to complain either way. Focusing on reproducing the "feeling" of a Star Wars movie (in which they were mostly successful imo) was the right decision here. They played it safe and introduced as few moving parts as possible, hence the unoriginal story. Considering the possible fan backlash for getting it wrong, playing it safe is a smart decision.
Actually some of the ideas in the OP, such as focusing even more on the OT characters, would have been terrible choices. You just can't build a movie on the wooden performance of Ford these days, and visiting these characters again after their arcs have been completed long ago would have been uninteresting and trite. I think the main cast of TFA was great both character and actor wise, and the movie would have been better of with less OT personnel, but I get why they handled things this way.
Now if subsequent movies and spin offs continue to be rehashes of existing stories, you'd have reasons to complain. Give them one safe play to get this rolling.