What is it that I'm confused about?
Trading is highly overrated.
I didn't produce any commodity. I produced nothing for exchange on the market. I wrote some stuff down in a blockchain, which is now a common good. Nobody has paid for it, and all are free to enjoy it.
You produced a commodity we call content. Steem is a free market of content and ideas. The action of writing that words is your labor. Sorry to break the news to you, but the $300 you got paid, someone paid it. You could as well publish the same words in a non-monetized blog, and putting it in public domain, but you chose to put it here, in a capitalistic free market, and you got paid for it.
And now you are the owner of $300 worth of steem.
(And well done, by the way, I have yet to make $300 with one post. More like +0.30)
Just don't claim you are against private property or trade or anything.
I produced no commodity. That's not really up for debate. It can't be bought and sold, because it is freely available for anyone to enjoy. Common goods are not commodities.
Steem is also not a free market, because it is not a market at all. In markets things are exchanged. Steem is not a market economy, it is a gift economy. Here things are freely given and shared.
You can clearly see this is the case, because the reward that I got for posting this was the result of actions that were completely independent from the act of consuming it. The people who voted on my post would have had the opportunity to fully enjoy it whether or not they voted on it. And by voting on it, they did not prevent others from enjoying it as well. It remains a common good.
It is actually up for debate. The fact that you're engaged in an economic endeavor by posting on Steem is a demonstrated preference for profit and property that betrays every claim made in the original post.
It is a free market economy. Since content is not a limited resource, my consumption or my likes do not restrict others from liking it. However, upvotes, do give your content more visibility, compared to other content that is not upvoted as much. And the reward you get $300+ is a limited resource, there is only a limited amount of money and steem going around. So... Content itself may be a common good, but upvotes, steem dollars etc are a total free market. And totally scarce, limited goods.
Welcome to agora! :D