Maybe I'm "old school," but investing for me means you buy and asset, hold onto it, and sell it later in expectation of a gain in value.

I think that option still exists for people to buy some amount of Steem, hope it doubles in value and that's their gain... independently of whether they are active on the social platform.

On the whole, though, I think you're right... this is an opportunity for content creators to become "stake holders" as a result of their effort and their "social marketing" skills. Which is a whole different kind of "sweat equity" investment.