I agree with what you said. I think there's also a third primary reason and maybe a fourth: 3) Developers are expensive. If you have a team of 5 developers eac

I agree with what you said. I think there's also a third primary reason and maybe a fourth: 3) Developers are expensive. If you have a team of 5 developers each being paid a salary+benefits of $1,500-$3,000 per week and they tell you a feature will take four weeks, management does a little mental math and says holy shit, that's a lot of money and it's understandably tempting for them to want to see if that team really needs four weeks, or if maybe it can be done in three weeks. (Meanwhile, as you said, the feature will probably actually take six weeks because developers cannot reliably estimate...) 4) Developers have a hard time saying "no." We have a culture of working crazy hours. Management knows this and often intentionally or unintentionally exploits it.