Those author levels are really only used when members are submitting to the Challenge. It's a way of rewarding members at their own level of ability. We originally didn't have levels of entry for the Challenge, it was a very disheartening thing for those just starting out. This way, even a beginner can be acknowledged for their entry if it is judged to be one of the best in that level for that topic.
However, from a browsing point of view, I can understand why readers would be interested in that sort of note on a profile, but it could mean they skip over some really good material by people just starting out.
Also, the level of ability is really judged by the author, so it would be very subjective. And I'm not sure all members would be that keen including that on their profiles in an "official" way. Many beginners do actually indicate that in their bio note on their profile. More advanced writers may include some of their writing credits. (Some don't say anything at all. LOL.)
Anyway, it's an interesting suggestion, and I'm interested to see what others think.