I think the key to recovering from over-commitment is to increase your rates. If you are over-committed, you are giving away your time for too little money.
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)
(FWIW, if you're a contractor who has more work than they can complete, I absolutely agree with your analysis)