In this video - the last para particularly, I marked the main idea in the middle where the idea of “one area not being adequately researched” is present (Line 7-9). How is that wrong?
Your answer isn’t wrong per se. It identifies the central issue the passage discusses, but Greg’s go a step further by emphasizing the need for further research into that issue.
Ask yourself: Why did the author write this passage? Was it simply to point out that the role of emotions in human-computer interactions hasn’t been adequately explored, or to highlight the need for further research into that role?
That’s why Greg’s choice captures the author’s overall message better.