Here is the kicker. Corey's shot was made with a standard cue and the success of that shot was the result of a tremendous natural talent and level of skill.
The cue allows the opportunity to make a shot like that, but it is not designed to make that specific shot. Corey needed to use a standard piece of equipment in a specific fashion to make that shot.
The jump cue on the other hand is designed to make a specific type of shot. It is a non-standard piece of equipment used to make one very specific type of shot easier.
Big difference there, I am all for having the full length cue jump shots such as Earl once played be a aspect of the game, it takes a tremendous amount of skill to make a jump shot with a full length cue over anything but a edge of a ball.
Using a standard piece of equippment to create amazing results is part of the artistry of the game of pool. Using a non-standard piece of equippment developed to make a specific type of shot easier removes alot of the artistry and skill from the game.
I believe that we are too fundamentally opposed to come to an agreement but I fully enjoy the repartee.
Using your example, a "standard" pool cue is an object that has been designed to do one thing exceptionally well, impart force and spin to an object ball in a comfortable and ergonomic manner for the user. No other object on Earth is as good for that task in a consistent manner as a "standard" pool cue. Can we agree on this premise?
Now, let's take the specific task of jumping a ball as a subset of the overall game of billiards.
For this purpose the "standard" jump cue is an object that has been designed to do one thing exceptionally well, impart force and spin to an object ball in a comfortable and ergonomic manner for the user. No other object on Earth is as good for that task in a consistent manner as a "standard" jump cue.
Sidebar: On the use of the word "standard". A standard is commonly thought of as the accepted and most widely used practice in any endeavor. On the subject of jump cues, they have been in use as short versions, i.e. jump handles and shafts for around 20 years now. The current versions are the state of the art and as such, after 20 years in constant development and use are the standard.
Now, if we can agree on the two definitions above we can move on to discuss your interpretation of Corey's shot.
Here is the kicker. Corey's shot was made with a standard cue and the success of that shot was the result of a tremendous natural talent and level of skill.
The cue allows the opportunity to make a shot like that, but it is not designed to make that specific shot. Corey needed to use a standard piece of equipment in a specific fashion to make that shot.
Actually the cue is designed to make that shot in that the cue makes the shot possible. Take Corey Duell and give him a broomstick and you find 100 of 100 people willing to give you 100:1 odds against Corey Duell making that shot using that instrument.
The only way for Corey to have any chance to do it is to use the cue designed to allow him to make the maximum use of his abilities.
Similarly, if we take a standard jump cue, a cue designed for jumping, and give it to Corey Duell then he can accomplish shots that mere mortals like me, despite all the hours I put in, can dream of.
However, and this I believe is your fundamental problem with a jump cue, if Mr. Duell and I were to have a jump shot contest and I were allowed a jump cue and he were not then I would beat him easily.
But, in a world where everyone is allowed to use the same equipment and equipment is no longer an issue then a person like me will never beat a professional player because the skill gap is too great.
You say that you are ok with jumping as long as it is done with a full cue.
Are you aware that some full cues are better suited to jumping balls than others? So is it not an inherent advantage if you take two equally skilled players who are both using only full length cues and one of them has a cues that "jumps" better than the other?
Isn't it better if both players have access to equipment that is nearly identical in performance so that only their skill is the determining factor?
If you agree with this then you should be in favor of jump cues because they bring the opportunity to every player equally.