That was partly my point. Rambo makes absolutely no sense as a kids cartoon, because it's a Vietnam war/trauma film, it's adult content throughout. But Robocop is not a violent or adult concept per se, it's just about a cop turned into a cyborg, so there's no problem with making a cartoon out of it.
A film is not "made for adults" just because the screen oozes with blood and sperm. Cut those scenes out, where is the "adult" content?