It seems like a similar argument for why some people say Bitcoin is a ponzi scheme. But Bitcoin has the underlying purpose of being a means of exchange. Steem has the underlying purpose of being a social media platform that rewards users for good content. Which seems like the way a social media platform should work.

Whether it will last the test of time or if a different platform wins out remains to be seen. But calling it a ponzi scheme seems to just miss the point of it.