Is the DNA-Genealogy Link not all its cracked up to be?

I've been skeptical since I first heard about the rash of DNA testing being done to 'flesh' out and discover family tree links that were previously only speculated about. There is too much emphasis in 'science' as the cure-all for everything, and anyone with a Ph.D. in one discipline is suddenly given credibility in another. While I do not doubt the veracity of the DNA evidence I am leaving as I type on my keyboard, I have trouble believing that DNA can be used to tell me conclusively where my ancestors originated.

I found this excellent blog about the subject of bogus DNA testing which I agree with. Today, Rootsweb is cluttered with DNA mailing lists for about every surname imaginable. I'm sure that these people are sincere about discovering who they are or perhaps linking together two distinct family lines that have not yet been connected by public records. I cannot however, believe that they are not being taken for a ride by companies who are capitalizing on the 'genealogy fever' that is so rampant today. Everyone would like to be related to Charlemagne - it's just not likely. DNA genealogy has created the new 'Indian princess' or '3 brothers from France' legends.

These DNA tests cannot really tell you anything conclusively about your family history, and the article states :

"But the general public doesn't know this, and no one seems to be telling them. More and more of these companies are popping up, the popularity of these tests has soared, and every month or so, a journalist (like this guy today) writes yet another story about how people are using this technology to unlock family secrets and "debunk family tales," even though it simply doesn't work that way. The upshot of so many of these stories is that people are being confused or traumatized by results from these tests. People with dark skin who came from black families and identified themselves as African-American are suddenly being told that they aren't African-American at all. People have sought psychotherapy over these results and questioned their families. But this is all based on a science that can't actually say you're not African American, (and most certainly can't say you're not Caucasian and therefore should qualify for minority scholarships and affirmative action)."

In my case, with a surname such as LeMaster, I'm pretty sure that I'm related to most who have the same name, whether they spell it with an 'a' instead of the 'e', or add the final 's.' In the work Lemasters U.S.A. 1639-1965, 90% of all Lemasters in the United States are descendants of Abraham Lemaster of Charles & St. Marys Cos., Md. There are others who descend from Johann Wilhelm Leymeister of Pennsylvania. How these lines are intertwined back in Europe has not been documented, and may never be. Would DNA testing tie them together? It would all be speculation without documentation.