Dude, they're used as role models to show you it can be done. You see people like Emily Blunt/Joe Biden (using your examples) that are always in the public eye and I'm pretty certain they've worked just as hard (if not harder) as others who stutter to improve their speaking. If these famous people are "active stutterers" as you put it in one of your comments, they're far from role models. Your role models are supposed to have been people that have overcame adversity and transformed themselves as a result. But if there's been any celebrity that has overcome their stutter (and you hardly notice any signs of stuttering in their speaking) they're somebody you want to be paying attention to. They're somebody you should be taking advice from.