One of the reasons I left academia is that my travel costs to work cost more than I earned. One of the reasons I left academia is that I was expected to mark essays and exam papers for free - work on which the students' future impinged. This was work that these students were getting heavily indebted for.

Passion for research or for teaching is used as an excuse to cover a multitude of HE's sins - but a love of what you do doesn't put food on the table. Nothing like penny pinching, unmanageable workloads, and stress, to erode the passion you have. It's no surprise that out of the many friends who gained PhDs around the same time as me only a minority are still working in academia. 

The current system is grossly unfair and needs to change or it'll get to the point where only students who can afford to will be taught by only lecturers who can afford to teach.