I think a certain proportion of the population like to fill in the blanks as you implied. Rather than accepting the fact that certain info is unavailable at this time, it makes more sense for them to complete the story in their own mind. You see it all the time when there are stories about people being arrested merely on suspicion of committing a crime. It gives rise to that odorous idiom "There's no smoke without fire". Then they crawl out with their pitchforks out, baying for blood. People have already determined their own truth before the facts are even disclosed.