>>714475276butyric acid is a byproduct of lipolysis, and so is found in high concentrations only in cheeses where this is a significant part of the aging process (such as parmesan, romano, swiss, provolone). other cheeses, such as cheddar, carry a lower amount. it helps to enhance the flavour, so your argument that its found in cheese doesn't really make any sense, because it does not help the flavour of chocolate.
it's found in hershey's chocolate because they use milk powder in their production rather than fresh milk. powdered milk goes through lipolysis when processed, giving the chocolate its sour vomit taste. hersheys also uses alkalised cocoa, which is supposed to reduce the bitter taste, but in doing so also reduces the chocolate taste.
in short, hersheys cuts corners and reduces cost of production, which results in a low quality product. the use of butyric acid in its production is not a positive thing, so defend it all you want, your chcolate tastes like vomit.