I don't think the analogy works with any business that has a physical product. Perhaps a better comparison is music. The latest single costs around $1 to download. The production costs must be much higher than anything I have ever produced for the microstock sites. And the artist usually has to pay other musicians and their managers, so they might only make a tiny fraction of that $1. They can make much more money, with high sales volume and they have lots of other ways to make money, like playing live but I think it makes a better comparison than selling coffee.
Musicians sell songs for private use, to a very much broader audiences. We sell commercial and editorial licenses. Maybe you should compare with the cost of a music license to use a song commercially.
I know its a bad comparison but I think its a bit better than coffee. I'm really not interested in any of these comparisons, as it doesn't get us anywhere. All these industries are unique and incomparable. We could only get paid more money if we all acted together and as that hasn't happened for many years, I think its not likely to work now. PocketStock have no power because they are right at the bottom of the earnings poll. If they want to influence the stock images industry, they need to become a big sites first. It's hard to see how that's going to happen.