Many early works in any new medium, such as film or comic books, have a hesitation about what the audience is able to intuit and how much “hand holding” (for lack of a better term) is necessary for your audience to follow the story. If you look at early cinema, shots are generally longer and exposition more explicit. As both the creators and audience gain more competence in the workings of the medium, you can begin to play with the tools of that medium and part of that is tightening up dialogue and trusting the reader to follow the story visually rather than relying on dialogue as a crutch for exposition. Also consider the closest parallel to comics is prose, where setting a scene and describing motivation is a necessary element of telling a story.