What's the difference between a DDT and a Pedigree....not much really except for the fact that Triple H perfected that move an puts his "all" into it. It's just a "bigger" move to hurt a superstar more.
Except that a DDT is designed to drop the top of the head directly onto the mat, which would theoretically impact the neck and spine. The Pedigree is a faceplant with the hands and arms locked above the back/shoulders to prevent the victim from lessening the impact. As a faceplant, it's more designed to shock the frontal lobe and cause severe disorientation.
Your point, however, is well taken. Most finishing moves are used by several other performers as less impactful moves. Everybody has a standing elbow drop, but when the Rock drops the People's Elbow, it's supposedly effective enough to end the match. A lot of guys use flying elbow drops, but when Randy Savage did it, the match was over. A lot of performers use variations of the Uranage Suplex, but Rocky (The Rockbottom) and Booker T (The Book End) both used it as a finishing move. And don't get me started on how many guys use some kind of a punch with momentum, but when Roman Reigns does his "Superman Punch", it's supposedly highly destructive and when the Big Show does a straight right, it always knocks guys out?
Basically, it's all part of the show. Just sit back and enjoy it.
wk