I honestly wouldn't take to heart anything that nasty, spiteful people say (even though that can be easier said than done!).

As a genealogist, who has also taken a DNA test, I can say that many people are surprised at what the results can throw up (you only have to watch any one of the tv shows about it). DNA tests are only a part of the picture when learning about one's heritage anyway.

My advice would be, when encountering such uniformed negativity, to just smile to yourself and think of the surprises their dna tests might just throw up for them. ;)