Yes, I think that the average person is adequately prepared for disaster, because most people have some flash lights and supplies in the basement. It is hard to say whether they are prepared, because most people cannot predict exactly what type of disaster is going to hit. But most people have the basics.
While most people may have enough supplies to last for a day or two if they are very careful, the vast majority do not have enough to fully survive past that point. The average person does not consider the possibility of a legitimate disaster during their normal day to day life and so does not prepare for one.
I think the average person doesn't have any plan setup for the future. If something really bad happens they are stuck, with nothing to do. I know I have enough solar power and batteries to last,however. I do not have enough food to last. It would be really rough on me.
Disasters are generally unexpected and they can come in a variety of different forms. Preparing for one type of disaster does not indicate preparedness for a different kind of disaster. I do not believe the average person is adequately prepared for disaster. It would take to much time, effort, and money to do so.