One could say the same of most social sciences.
Every day tons of people form garage bands and have dreams of becoming rock stars. But...they do so knowing they almost certainly won't make it.
This professor said that starting a doctoral program should be viewed the same way, as a sort of moon-shoot that will take a lot of time and resources from other pursuits. If you're okay with that, go for it, and if you're not, find a path that works better for you.
Unfortunately, the administration of the school he worked for told him he would be removed from his position if he shared this philosophy with prospective students.
In contrast, universities and their faculty absolutely need a large supply of low-wage teaching and research assistants to function today.
The students who did their PhD the quickest in my program did exactly that. The students who failed or took longer usually slacked off, skipped days, focus on other stuff, etc etc etc. I know one person who disappeared for weeks and then quit. Thing is, he could still have come back and resumed his PhD even after that disappearance.
You could argue that it’s difficult for students to plan and do work on a consistent basis while having full academic freedom and very little direction (my advisor when I joined with almost no research experience told me to “read papers” and then we’ll discuss what to do after you do; like what does read papers mean anyway; I had no idea at the time but I learned by asking fellow students). But it’s not something that you get lucky in. It’s something that you keep at it until you finish it.
I got a bachelors in Computer Science and then worked for 15 years before going back and getting a masters. While there I was asked to work for free on numerous occasions, we can call if different things, but that's how I saw it. Already knowing the value of my labour I finished my masters and then left. I definitely had the option to continue with a PhD, and I'm almost certain that had I applied I would have been accepted. But I just wasn't interested in being exploited.
I remember one class which I dropped in which the entire class was project based, and we were to work on projects that aligned with the research of the professor. On the first day there was no syllabus given, so I asked what the readings were and received a grumpy response basically saying, "Readings, yeah there will be some readings." Or something similar. It was incredibly clear the instructor just wanted grad slaves to advance their stuff. I dropped that class, but I could cite numerous other examples.
I paid for the privilege of working for free and learned some stuff along the way. Maybe I should have spent the two years and money on travelling and seeing the world instead. I likely would have learned more, but I wouldn't have this fancy grad degree.
I don’t ask students to do research projects because I expect “free labor” from them (unless they’re my PhD advisee, in which case it’s just poorly-paid labor.) In fact, most of the time I expect that undergraduate and MS projects will fail, or only be partially finished simply due to the schedule constraints those students have with other courses.
For students who are actually interested in conducting real research, the value to the student in being advised by me comes from the fact that they’re working on a research project that’s in my area of expertise and interest. The value to me is that sometimes I learn something new. There’s much less value in my advising students to do projects in areas that I wouldn’t be interested in researching myself, not because I’m looking to cash in on students’ labor, but because I won’t be able to offer them as much guidance.
I’m thinking someone could work at Facebook over the summers while studying because they take PhDs