The point of the article is that the interview system is broken because:

• What makes you sure you need a “software engineer”, you are hiring for a specific position/job. Can this person do it or not. You are trying to evaluate his future skills but are you sure you can actually retain him.
• Yes, you have to spend 3 hours preparing for each interview, we are not robots. Questions should be relevant to both the job and the person you are interviewing. That 3 hours (reading his blog, info, etc.) will actually save you the effort of conducting anymore interviews, example stated in the article is one of the startup actually needed a person with experience in video streaming. They could have saved their time, money and energy but conducting a research into the people they are trying to bring on-board.
• I know people who can implement any algorithm live on a white board, but when facing any real problem they fail (and crash).
• The main problem of this article, is that I somehow expected the author to suggest better alternatives to hiring not just ranting. It would have made more sense.