Ethics will depend on the developer's needs at the time, and there is a big difference between ethics of the developer themselves and their employer's ethics.

They may take a less ethical job to put food on the table for their family.

They may take a less ethical job to build a financial buffer zone allowing them to take a more ethical one in the future.

They might not have the luxury of working a more ethical job - either picking the least worst option or perhaps only option due to reasons far beyond their control.

I consider myself extremely fortunate that - so far - I've always been able to avoid industries on my moral blacklist.