As a fan of the Lost World subgenre, I have developed a - perhaps misguided - patience with the genre's worst elements, namely racism, a problematic love for imperialist structures, and gender politics of the most dubious kind.
Therefore, one would expect me to be all over Irwin Allen's adaptation of the - lovely - Arthur Conan Doyle (my democratic principles laugh at your titles) novel which gave the subgenre its name. Curiously, one would be wrong in that assumption, for I do in fact enjoy only about twenty minutes of this version of The Lost World. In part, I blame Allen's insistence on making a film whose politics often feel more problematic than those of a book published 48 years earlier, which is an achievement the film even manages to repeat by including a romance much worse than the one in the Doyle novel. Even worse, the film seems to assume people care about the human element in this sort of film and so puts a lot of emphasis on it. Too bad people generally don't, unless the human element in a Lost World movie is either very well written or enabling exciting adventures, neither of which applies to the film at hand.
Lost World 1960 doesn't rise in my appreciation with using the animal snuff film version of dinosaur special effects, that is, the responsible parties glue fins and horns to helpless reptiles and let them fight or fall to their (actual) death, while the camera lingers unpleasantly. It's a bit like a junior version of Cannibal Holocaust without the self-consciousness, and also so vile I find it difficult to even laugh at the movie for its idea of how a Brontosaur or a T-Rex are supposed to look.
And I still could ignore or pretend to ignore all this if the film would just throw me a bone of actual entertainment for more than just once or twice during its running time. Allen's direction is just too bland, the characters just too uninteresting and/or annoying, and the film just too lacking in visual imagination to distract from the basic unpleasantness of its worldview in theory and practice (as demonstrated by the way Jill St. John and all brown people are written, as well as the animal killings - one might even suspect a connection between the two). It's just not The Lost World I signed up for.