The article is about someone who works a steady non-contract job who signs up for personal side projects and research stuff at work, I'm not sure how you think

The article is about someone who works a steady non-contract job who signs up for personal side projects and research stuff at work, I'm not sure how you think "increasing your rates" applies in the situation. (FWIW, if you're a contractor who has more work than they can complete, I absolutely agree with your analysis)