My mother used to do that....and a friend of mine's mother does the same thing. Our theory is that by making a problem even worse and more complicated, they can take charge of the situation, the way Napoleon took over France during the chaos following the French Revolution(s). It makes them feel in charge and important. My mother used to enjoy bragging to her friends about how she solved a major problem I had--a problem I never would have had at all if she hadn't jumped in and complicated a minor difficulty.
Some people like making mountains out of molehills....they love the drama they create.
They have nothing better to do.
It is all about drama in most cases.
Because they like being pitied
They like to have interesting stories in their lives, so they instigate fights and create drama and chaos. I see many drama queens in my life; the one that amazes me most, I call 'Mean Girl'. She works at the same company I do. (I was going to write, I work with her, but she can't work with anyone female, she gets along and flirts with the men) She rats out her female co-workers and lies to the bosses, starts fights and bosses some woman around. She's truly malicious, and the men ignore her behavior towards women, even the bosses! Drama and Chaos! She loves it.