A lack of paragraphs in your writing often leads to run-on sentences as well. Because the writing isn’t structured ahead of time, the writer tends to become more and more vague over time. The last few sentences, then, often become the loosest and least well-thought-out. Fixing paragraphs usually reveals which sentences are run-on sentences as well (It’s worth saying that I disagree with the part here about the taxes, but that’s what the student wrote).