Why do PhD students quit and what can universities do to prevent it?

Three years ago I was just about to start writing my PhD thesis when I eventually came across one of the most pertinent questions one can find about a research career in academia. The question was posted by a researcher from the University of Tartu (I believe this is an university in Estonia). I read the question time and time again and the answer that I thought was the most appropriate and reasonable to explain the problem postulated was so evidently clear to me. Nevertheless, as I always do, I also read through the many other opinions different commentators had left to conjecture on the issue presented. I agreed partly with a few ideas there posted, with others I was in total disagreement. I then decided to contribute with my own opinion that in my personal judgement best approached and explained, as a whole, the problem that was brought to analysis. 

I couldn't believe that three years in my comment would still resonate in other people who agree with me on the different points covered, and made it the third most recommended comment on that specific topic. My disbelief is not based on any lack of confidence/validity on the things I write or think or say. But because the topic itself, be it for students and/or PIs, is always a delicate one (for none of the involved want to hurt any sensitive spirits) people usually approach it from a safe standpoint. Respectfully, and in a considerate manner as then, I am also posting it here for you to read and think about it.

The Question

My Comment

Find here the link to the post where you can also read several other comments from very academia-experienced people.

Why not leave your own opinion here or there?!

Thanks a lot.

Post image kindly taken from [https://nicholaskawa.wordpress.com/2018/03/22/how-academic-hierarchy-shapes-the-distribution-of-precarity/].