I think people make too big of a deal about yeast (starters really) in general. All yeast does is eat, fart, and multiply. In theory, even if a single yeast cell makes it into your beer, it will eventually multiply enough to totally ferment your beer. Wyeast smack packs pitch 100 billion cells. The only time I make a starter is in a very high gravity beer where the sugar content is so high it can actually overwhelm the yeast. I suppose with a starter you reduce the chance of infection by bringing up the alcohol content more rapidly, but you also introduce other potential problems like blow-off, etc. Just my two cents.