My understanding is as you have suggested it is. Yes it seems really skewed but in the beginning of Steemit, last year, posts were often earning a few hundred dollars each...and some steemers were making $1000's per post. 3 days after I joined the platform, @dollarvigilante arrived with a tonne of instant followers from YouTube and his personal blog. 1 of his very first posts paid out $15,000 SBD. I suspect it is theses very astronomical pay-outs that is making the charting look off. (In my humble opinion.)