Great question, I'd never noticed it. Looks like it's based on number of posts, which is no different from the Member Title column in this grid:
I'm a less is more guy myself, so maybe we should just remove the Reputation? What do you think?
You mean hide it on the profile? Doesn't really add any value so yeah why not.
I wasn't able to remove the Rating. But I changed the Rating Levels so all 10 Rating Levels aren't being used. And we both now land in the same 10/10 Rating Level with over 200 posts. Happy to make more changes too based on suggestions.
This is what the Rating Levels used to look like:
This is what they look like now, with 200 posts being the top Rating Level: