Some critics of American Beauty really want to focus on the whole "critique of American life" angle, but really, this is a movie about love and family (with some sex mixed in too, of course).
Sure, Lester's journey toward self-discovery is pretty selfish and isolating, but his whole drama is largely about trying to figure out how to connect meaningfully with the world around him, including other people. At first, that journey is all about sex, but he ends the movie (and his life) thinking only about his family.
Questions About Family and Marriage
The movie is all about the Burnham family and its dynamics, but do their issues ever get resolved in any significant way? If so, how?
Is there a model of a functional, healthy family in the film?
What do you think happened to Ricky's mom?
Chew on This
The Burnhams never really work out their drama. They find it impossible to communicate right up to the end, and it's a failing of the movie that we never really see them resolving anything.
It's not exactly true that the Burnhams don't make some progress as a family. At the end, both Carolyn and Lester seem to appreciate what they had in their family life—too late to enjoy it, sure—and it means something that they seem to come to that realization right at the very end.