I cast your attention to statements made by NASA's own scientists here:
Including: 'He did, though, admit to New Scientist that the view of the expected plume of debris from the impact could be blocked by "a large mountain that's about six kilometres tall or so on the northern side of the crater", meaning that "the ejecta has to fly up higher before it becomes visible to Earth observers".'.
I also point you to the AC's comment on that article entitled "That's just great", which nicely sums up the way these things seem to turn out.
If I were to change the scope of a project to allow it to fail to live up to the brief I would, quite rightly, feel disappointed. You don't have to be a rocket scientist to understand when a project is disappointing.