I think at the very least we can agree that it is the employee's job to inform their superiors of feature creep, looming technical debt, and whatever bad practices they see.

If you're fixing bugs in production because your manager hasn't addressed longstanding technical debt, then yes, you shouldn't feel bad about the bugs that slipped through against your advice. In that case, I think your indignation at working extra hours without getting paid would be justified.

Ideally, we would do proper estimates upfront without being pushed to grossly underestimate features because so-and-so thinks it should only take a few minutes.

Pushy managers and bad employees are made for each other. It's a feedback loop.