It doesn't matter how good my evals are or how big my contributions. It doesn't matter that there are multiple multi-million-dollar revenue streams which exist in large part due to my contributions. It doesn't matter that I have been told I am good enough that I should be promoted to the next level. Raises barely exist, let alone promotions. Because theoretically some other engineer could have done the same work I actually did, the fact that I'm the one who did it doesn't matter and I deserve no reward for doing it beyond the minimum money necessary to secure my labor.
Under those conditions, why should I - or anyone - do any more than the minimum necessary to not get fired for cause? If the company doesn't see me as more than X dollars for X revenue, why should I?