I think this is one of the most important pieces of the puzzle. Graduate students are so common they they can't differentiate themselves from the rest by simply being graduate students. They need to do more to be above the rest and this leads to the bad circumstances.
Commodification. The easier you are to replace, the lower your market value and the weaker your negotiating position. Software developers can earn six-figure salaries and work in offices that look like holiday resorts because demand for their skills massively outweighs supply. Grad students get treated like dirt because the supply of grad students vastly exceeds demand.
Most people who choose to be grad students have better options, which we should encourage them to take.
