Why is there alot of movies about world war 2?

It was a really big war.  It's before the great majority of us can remember.  A lot of good stories came out of it.  War movies made in the years following the war were all rah-rah, celebrating our great victory.  But war movies today realize how futile and senseless war is, which just make them more dramatic. 

Because that's the last war our country was in that didn't start because of a lie.

Because a  lot of stuff happened........all over the world. .....so there was more than a few stories to tell. 

It was a pivotal moment in the C20.  A good v evil type deal.  Lots of stories, lots of change happened in a relatively short period of time.  History was made.  Hence lots of material both fiction and non fiction for writers and film makers.

Because it's a war that will forever have an impact on civilization.

Because the war dominated people's lives at the time.

It was to make Hollywood actors more money
As people wanted to see that stuff back then.