On another side: Why does WW2 interest people so much?
There are many reasons why it could interest people, but each person will have slightly different reasons.
Some, in no particular order:
It was fairly recent, so many people have a personal connection to it.
So many people were affected by it that it is very easy to find people connected to it.
It was one of the most devastating events in recent history (nothing gets interest like millions upon millions dead).
Video. It is the first major war with a significant quantity of decent video footage, and colour too.
But from my perspective, the most important reason is simply its popularity. There are so many games, movies, books, ect based on it due to its popularity that they draw more people in. So in a way it is self supporting.
On another forum the question "What got you interested in WWII?" was posed, and it was very common for people to either start with stories from family members or look up the history of those family members, else they watched a movie/played a computer game.