Speaking as someone who worked in technical program manager for the worlds largest user of technology... I couldn't agree more!
It's logical to believe that schedules can be set and achieved, and they can to a certain degree. But in flight simulation with all the variables and changes we continually have to deal with, it's just not possible. Of course we have internal schedules, but every time those have been published something happens that takes the project off track. This is the very reason why other aircraft developers no longer publish schedules and timelines... just can't factor in all that we have to contend with and release dates publically - that's simply setting oneself up for failure and disappointment for end users.