@Ernie. 
The reasons are actually many-fold. Influx of Outsiders? Sure. Also, Nome's overall population (in the top 10 statewide). It is also one of the older "cities" in the state due to development during the Gold Rush. And the annual spotlight of the Iditarod helps influence it a bit too. 

Specifically in regards to rape/abuse - that is what a full-time police force will do for you. A cessation of violence and swiftness of intervention tend to help maintain order. (Although a Nome officer did kill a young woman ten years ago. Even with that factored in, Nome still safer than a village.)