I don't sense any dark connotation for the word. I've seen it used most often in a pretty value-neutral way to describe any group of people living outside their

I don't sense any dark connotation for the word. I've seen it used most often in a pretty value-neutral way to describe any group of people living outside their country of origin. These days most diaspora are composed of economic emigrants who have left their homelands voluntarily in search of opportunity. It's also the title of a very good science fiction novel that I would say treats the word without negative connotations.