Steemit has value and many of these posts have value. But they are no more valuable than posts on any other internet blog. The value of Steem (the currency) was created by speculation. The speculation was on the growth of a new currency not the value of blog posts on the internet. So I don't believe these posts are worth thousands of dollars to anyone. But this positive feedback loop that was created has made that so. At least for now.

I posted some of my thoughts on the value of steem here if you're interested https://steemit.com/money/@maniac/we-might-be-overvalued

I also found this. He uses game theory to delve into the economics of steemit. It's a three parter with more to come.
https://steemit.com/steem/@biophil/what-does-game-theory-say-about-steem-part-1