That depends.  

Being pressured to fly in weather that is above minimums shouldn't have to happen.

Being pressured to fly in weather that is below minimums shouldn't happen. In this case, it's a safe bet that investigators would take a dim view of pressure to fly. That's where getting it in writing comes in. It prevents post-mishap backpedaling as well as chameleon leadership. Writing gives attorneys something to work with. Legality is ultimately for the courts to decide.

Chameleon leadership is when a supervisor gets to say, "I didn't know he (or she) was taking such risks" after pressuring them to do it in the first place.

I agree with you that people shouldn't work at such places. Only the angle is different. A prospective employee should do due diligence before taking a job at a irreputable company. He (or she) should not wait until they are there for a real schooling. When bad-mouthing a company is limited to onsies and twosies, it can be disregarded. When an entire army of former and current employees bad-mouth it, there's probably substance there.