A strong part of the protestors are young farmers. Set on taking over their parents farm and continuing the family business. And they probably want the same for their kids as well. It's really puzzling they take this stance, especially since the majority is also anti EU, which is also against their best interest, because most of their revenue is from export, which would suffer havily when a Nexit would ever occur.
Just a guess, but I know some farmers. What I get from them is, that they are all about freedom to do what they think is right on their own land. Anything that brings regulations to their farms is felt as an attack. To be honest, I can understand them. They work insane hours all year long, constant pressure from the markets and society and every year there are more laws demanding their time and resources.
That some of these laws might be necessary is lost in their daily struggle.
No, they don't care. They, like many older people in other countries, feel that they have a right to their "way of life". It's a strange failure of thinking when someone believes that they have a right to be how they have previously been (especially when their previous behavior has been demonstrated to be foolish or harmful to themselves or others).
Source (Dutch): https://www.trouw.nl/binnenland/vooral-jonge-boeren-worden-s...