Hello Tessa. Nothing is wrong with seeing writing as a way of making money. I have also always written because that's what writers do. The problem here is that Medium has never promised you can write for money. If you want to write for a set amount of money, then you can pitch your ideas to newspapers, write content for businesses, or do what I do and write plays/screenplays. I don't write those for free, nor do I suspect do you.
Medium hasn't said it will do anything other than host your writing. It has tied its monetary policy into that writing process but it has never explicitly said 'you can make money writing here'. That's fine. If I write here I expect it to earn next to nothing, because that's all I've been promised. I'm not a genius. This isn't a professional gig. There is no contract in place.
We write. There are methods of securing a set wage for your writing and those aren't available here. That's not what Medium is. The idea that Medium owe writers a certain amount of money comes entirely from a sense of entitlement, based on a) earnings elsewhere or b) previous earnings. The sooner this is dropped from the concept of writing on Medium, the better in my opinion. I've made money here, but I make far more elsewhere and that's how it should be - because this is a platform not a contracted writing gig. :o)