Not only Dr. Jones was that irresponsible and criminal, if you think about it, he was absolutely useless on "Raiders" AND he caused World War 2 and the Holocaust.

If it wasn't for him, the nazis would have never found the ark and it would not be stored in a lone box in a gigantic warehouse.

And if they did, chances are they would take it to Hitler and open it before him (the Nazis would probably convince Belloq to do so), thus melting Adolf Hitler in a "80s Industrial Light and Magic" way before WW2 and saving millions of lifes.