Took a quick look. If you want my take, your basic tutorials are, well... too basic. They describe fundamental language principles in a well-established programming language for which there's already a wealth of material available. Frankly, there's already a million articles and books that cover that.

IMHO, you need to write about some cool hot or esoteric feature that solves a specific problem in a new way. Or about how a particular crash bug ended being based on something that everyone else thinks works one way when in fact it works the other way.

Do a search on a topic. Are there already thousands of pages that cover the same thing? If so, write on something else.

Trust me. It's possible to do a lot better than $1.50 an article.