Because, LLMs are touted to be the silver bullet of silver bullets. Built upon world's knowledge, and with the capacity to call upon updated information with agents, they are ought to rival the top programmers 3 days ago.
They might be touted like that but it seems like you don't understand how they work. The example in the article shows that the prompt is limiting the LLM by giving it access to only 2000 tokens and also saying "ONLY OUTPUT ...". This is like me asking you to solve the same problem but forcing you do de-activate half of your brain + forget any programming experience you have. It's just stupid.