I am not trying to get in the middle of a food fight on this topic since it doesn't matter to me one way or the other whether Madmax or Cheesy or anyone else chooses to buy a starter from sourdo.com, or get one from a Carl Griffith source, or culture one from a piece of old dough, or make one from wild yeast at home. But I think Cheesy's comment is technically accurate--I believe it is called Darwin's principle of "natural selection". The wild yeast that is pervasive where Cheesy lives is there because it has been able to survive after millions or billions of years, and nothing is about to eradicate or weaken his wild yeast anytime soon. If the wild yeast Cheesy has captured works for him, I'm happy for him.
Although I have read Ed Wood's book, I can't speak to the sourdo.com starters because I haven't tried them to offer an opinion one way or the other. I assume they are good, quite possibly the best and maybe worthy of trying. But I have made starters at home based on wild Texas yeast and have gotten good results. I know others all around the country who have made their own starters and they, too, say that they have gotten good results. Nancy Silverton and Amy Scherber, two very well known and highly regarded sourdough bread bakers and authors, recommend that bakers make their own sourdough starters from wild yeast. I think where most people go wrong with their starters is that they don't care for them properly. Usually they let them get too acidic or to have too much alcohol such that the finished product (bread or pizza crust) tastes far too sour and is almost unpalatable. But this phenomenon is not unique to homemade sourdough starters. This can also happen with a starter purchased from sourdo.com or anyone else.
My view on the subject is do whatever you want, whether it is based on personal economics, the curiosity and fun of experimenting with different ideas, personal enlightenment, or whatever.
Peter