On almost every single project I’ve worked on, hard deadlines have nearly always been the cause of any stress or frustration that arises. One day you’re asked to make rough estimates and then next thing you know they become pegged to a date in the future that you must meet at all cost (But you said you think it would only take X days!). Even worse is when someone non-technical makes the estimates for you and passes them down from on high (Look, this is the all the time we have, I’m sure you’ll be fine!).
Why do we still insist on having hard deadlines? Yeah I know, we asked for more features but now the project is “late” so you’ve failed to do your job. Yet, if the deadline wasn’t concrete, the project would have more features then initially scoped and delivered in a timely fashion, you’re a success!
New features are always requested, changes are always wanted and bugs will always be found. If everyone just accepted (understood) that writing software isn’t exact science then we’d all have a lot less stress to deal with and we can stop feeling like a failure for not meeting that pie-in-the-sky deadline.