To those commenters who write that deadlines are necessary because many, or most, employees are not motivated self-starters, I posit that this is a symptom of poor leadership, originally by their parents.
Yes, it's possible to force people who don't want to do things by using fear and control, but it's much more effective to use what we know about human nature to generate a 10x output that is sustainable and actually enjoyable.
Ineffective leadership is not an optimal solution for ineffective leadership. It's a downward spiral.
This reminds me of the people who spank their kids because they're disrespectful, but, as we know from research, spanking kids makes them disrespectful. Spanking kids just makes them pretend to be respectful while being increasingly disrespectful.