Because as far as we know stuttering is a thought/vocal production timing issue. Its really hard to effect one without the other in a consistent way. Lets say your stuttering is made worse by anxiety, well then beta blockers might work to lessen the exacerbation due to anxiety, but would it treat the underlying stutter? You jaw still worked fine, like you could click your teeth to a rhythm so that wasn't a problem. Though production is fine if you aren't talking; you could evil villain monologue in you head all day. How do you specifically target the timing of part of the brain? What are the specific pathways that are off? Why can stuttering people sing fine? I personally think stuttering is related to the yips, so if you want to see it in different format go watch Charles Barkley hit a golf ball or Chuck Knoblock (sp?) throw to first. If these millionaires can't solve it then all that is left for us is to try every party trick to find something that works for you. Speaking in an accent mostly works for me, I hope you find something that works as well for you.