But it's in the writer's best interest that I only read 1 article, theirs. Also, it's probably best for Medium that I read fewer articles- at least then some writers earn a reasonable amount of money and stick around instead of everybody earning a pittance.

That's a valid model if there are very few readers. The number of paying visitors is probably monotonically increasing with the amount of content. Maybe medium has created a model about the critical mass of paying readers to sustain the ecosystem.