Though I love the fun family orientated use of the Simpsons, in certain industries, this use of character would be appalling when using it to present a type of persona due to a lack of needed sophistication or contrasting of the company's brand, say the client were to be Vogue. I do think an illustration that sat closer to realism would be more effective as a starting point in depicting a persona visually.
Architects and environmental designers often use silhouettes which are very typical and avoids possible stereotyping. The reason for avoiding such issues in the first place is that stereotypes do not let us see the real person beneath, however silhouette usage poses the same issues if used as a mugshot. However if you are depicting your persona's behavior within a physical environment, then its use would be perfect. Say illustrating users of a doorknob and how they approach it.