Given the modern fascination with Extra Features and fans learning as much information about movie productions before, during and after they're filming, it's inevitable that Deleted Scenes have become as big a part of film packages as Director Commentaries.
The inherent exchange involved in seeing those cut scenes gives fans unprecedented insight to the director's creative process, and when the scenes are meaty or change things dramatically, the reasons behind those decisions become even more interesting. Sometimes, it's a matter of pacing or wandering tone, and the directors include the scenes to show off their craft and to show they recognised possibly toxic material that could ruin their movies.
But then sometimes there are scenes that we see fragments of in the marketing, or film-makers reveal the existence of that never make it out of the editing suite. And they don't always deserve to be cast aside like the alternate takes or the flab excised from remaining scenes, because some of them sound truly interesting or enlightening.
Unfortunately, fate seems to have conspired against a worrying number of excellent sounding scenes and no matter how much you'd probably like to see them, you just plain aren't allowed...