I can understand the interest. In much the same way as I can for people who do these online personality tests etc. I guess it's what you then think/do with that info that becomes the issue.
Personally, and as someone said earlier, I'm not overly concerned beyond that natural curiousity, the 'parlour game' interest. I wouldn't go any further though. That I have ancestors is a statement of the obvious (actually, wouldn't it be cool if such a test found NO trace! Now THAT would be something!) Who they were, I'm a bit meh about. Ditto for my personality; it is whatever it is (again, unless the test showed that I somehow didn't have one)
I am who I am and from wherever I am. I stand here as living testimony to it. What I do today and forward from here has more interest to me (sorry if that sounds a bit 'right on') How I got here holds less interest for me. And, no, I'm not a history buff either
As with all things of idle curiousity, go for it if you have the cash. I buy maps sometimes, not because I plan to use them to navigate but because, for some weird and wonderful reason, I simply like looking at them. I don't question it any further.