Reduce demand for Hops
If this GM yeast reduces the demand for Hops for traditional brewers it is a good thing (from my point of view)... It means that I will be able to get the good beer (without the GM yeast) at a reasonable cost as the cost of Hops will drop or stabalize due to the reduction in demand... and the heathens that drink the crap, GM Yeast based, beer won't know the difference.
Biting the hand that feeds IT
