They would much rather confidently repeat a date that is totally unfounded rubbish which will have to be rolled back later, because then they can blame the engineering team for not delivering to their estimate.
If you had a deadline - say thanksgiving or something - and you asked “will the work be done by then” and the answer was “I’m not going to tell you” would you hire the person?
The no estimates movement has been incredibly damaging for Software Engineering.
When you ask for a firm estimate, you are basically asking to be lied to, and the contractor happily complies by telling you a lie.