That might be moderately true for, say, someone developing a new app feature that gets shipped to users who aren’t expecting it. However, it’s not true at all when the software development output is a gating feature for real-world contractual obligations and other such business drivers. In that case, target dates must be carefully forecasted and estimates must be performed with great care and detain. This doesn’t guarantee that a target date will be hit, of course, but it’s not impossible to produce estimates that are reasonable accurate a large percentage of the time.
Estimation, planning, and progress tracking are difficult skills that must be learned, but they’re not impossible. I suspect many of the developers who believe that target dates are always arbitrary, pointless, and impossible to estimate have mostly worked in big cash-rich environments where it didn’t really matter when a feature shipped. If you go to the other end of the spectrum and talk to engineers who work in industries where target dates are critical you’ll discover a lot of people who are very good at breaking down projects and accurately estimating dates without relying on crunch time to get things done. It may sound impossible if you’ve never worked in an industry that requires such precision, but it makes sense after you’ve worked in such an environment for a while.