And think about it, if Steemit & co is only there so that you can "make money with your posts" and nothing else, then people are going to keep coming in, doing that, and selling STEEM on the exchanges since that is actually what "making money" entails. Then the price will forever be slipping because why would anyone actually buy it?

Great point, so many people here get hooked on making money and forget this.

The promise of Steem in the beginning was an alternative to the advertising fueled model for social media (as well as a censorship resistant medium). But if people wish to cash out, the fiat money has to come from somewhere and without some form of commerce or utility that only leaves speculation.
For that reason I think it's vital we have an feature to support commerce on the platform. The single most important feature I think is a "stable" asset such as SBD.

Where we can achieve a stable asset or not is an entirely different question.