Several of my friends have seen the movie.
The youngest of them - in his 20s - thought the story was lame and was put off by the "galactic scheming." He felt like the movie was really stretching to find motivations for the actions of the characters. Kylo Ren is the one he complained about the most, he said nothing he did made sense.
The oldest of them - in his 40s - enjoyed the new ships, redesign of older ones, and overall special effects. He said the depictions of space battles were well done, but the camera moved a little too fast for his taste. He didn't have much to say about the plot, other than to recount some of the facts that happened.
Not having seen the film, I can't comment on why there may be a different appeal for different generations. The thing that bothers me about the movie is the distribution deal Disney worked out with theaters. To show the film, they had to agree to keep it on screens for at least 4 weeks.
I remember going to see The Force Awakens on a Friday night a few weeks after it was released. The theater was empty. An usher walked through the theater a couple times just to make sure we were being behaved. That memory stands out more than the film.
I don't know about you, but watching a movie in an empty theater feels creepy.