People posting family pics aren't doing so to make Facebook money. The reasons people use social media are generally unrelated to ROI, and the focus on monetization has been a mistake on Steem, from the standpoint of onboarding masses of people. It has attracted a particular market segment, and not the mass market, which is not seeking mere economic return from using social media, but more valuable aspects of society.
The models are comparable with trivial facility. The market segments served by social media are difficult of compare, because of the complexity of society, not because of the marked differences between social media platforms, whose differences are relatively small.
I was replying to your statement that social media is the most profitable business model.
There's no question that the focus on monetization for the users was a mistake, and I've always said so. It's not the content providing the value on the other platforms, it's just the vehicle to make people give away their profiles. Content here has no value in itself either. It can bring more eyeballs, but that only creates costs for the interface operators, or some revenue if they manage to sell adspace. But it cannot be used as a vehicle like at other platforms.
Even if steem had an interface appealing to the mass market, there'd still be no money to be made from that for the users.
The only thing giving steem (monetary) value is use cases for the token itself. RC and curation rewards are such, if they create enough demand by themselves is not clear yet.