Why did my grandfather translate Mein Kampf?

Whenever I tell anyone that my Irish grandfather translated Hitler's Mein Kampf, the first question tends to be, "Why did he do that?" Quickly followed by, "Was he a Nazi?"

Simply answered, No he wasn't a Nazi (more on that later) and why not translate it? He was a journalist and translator based in Berlin in the 1930s and that's how he earned his money. And surely it was important for people to know what Europe's "Great Dictator" (apologies to Charlie Chaplin) was about?

Certainly my grandfather and many other non-Nazis thought so at the time. Let's also not forget this was before Hitler became the most notorious figure of evil in history.