I was debating about this myself, think I've actually asked the question before too. I don't necessarily know how much it would be worth to the person actually getting the certifications, but how much is it worth to potential customers? If you take someone who knows what they're doing but isn't certified, or take someone who really doesn't know all that much but has a Silver level cert, who would the average person go with? Yes we all know how to tell if someone knows what they're doing or not, but is it one of those necessary evils? Or what "proof" of competence is a bowler supposed to consider when choosing a coach?
For example, when my boss and I are both in the shop, people will come in and automatically start talking about balls with me, because I have several big scores and a big average and he doesn't. But at the same time, he gets the majority of the coaching requests because he's Bronze certified and I'm not. Realistically, my boss has taught me everything I know (though he isn't responsible for my crazy conclusions at the end of my abstract rabbit trails), so either one of us are perfectly capable of doing it all, but our resumes are different, and that attracts different people with different questions.
So how do you reach the largest audience possible if you don't have a certain amount of "feathers in your cap?" If the only thing that stands between me having a Bronze cert is paying for and attending the class, the frequent question is, "Well then why don't you do it?" Because the only difference between having it and not having it is a few hundred dollars and a couple day trip . . which isn't worth it to me personally, but is it worth it to me in the eyes of potential customers?