This is true. I think a lot of complaining about grad school comes from four areas: 1. As you point out people who become grad students are often fortunate pe

This is true. I think a lot of complaining about grad school comes from four areas: 1. As you point out people who become grad students are often fortunate people. They already have a college degree. They are able to do well enough at school to be accepted into a graduate program. This usually means that they could be getting paid 2-15X more while doing far less work at an industry job. So in comparison grad school is miserable. 2. Unlike a top high-skill job grad school is a uncertain career track. You can find out that you spent between 3-12 years of our life with very little to show for it researching something it turns out no one, including you, cares about. The uncertainty gets to some people. 3. PhD programs can place an enormous amount of pressure on the student to be independent, have new ideas and execute those ideas well. This can be a frightening experience. 4. In some fields very strange workloads placed on the student. For instance in some labs students run experiments that require performing a task every 40 minutes for 36-72 hours straight. If the task is not performed perfectly weeks of work is lost. The experiment might involve dangerous chemicals. This is like being a long haul trucker or sound engineer.