I believe the tone of this film was lost on most people. It was also marketed wrong. It is not a family movie, a children's movie, nor even a teen movie. A tongue is planted firmly in cheek as every 60s-70s sci-fi trope is thrown at the viewer. Genuinely pretty funny at times. Not essential viewing by any means, but certainly not terrible.
Rick Marshall seems to be an interesting analysis in the ineptitude of science, displaying the cavernous distance between pledged allegiance to logic, structure & order and true emotional motivations, resulting in more questions about intentions and ability than discovery. In addition, by comparison, it appears that progress is actually made by intelligent students or the instinctual laymen, despite Rick's dumb luck.