I understand your points but I must also respectfully disagree with you as well. Let me share my qualifications before I answer your points.
I have been playing pool, billiards and snooker for 24 years, since I was 12 years old. In Europe I was a pool instructor. I have devoured most books and tapes on how to play pool. My high run in three cushion is a ten. My average in 3-cushion is however a dismal .00000000001

since I do not play it at all and have played very rarely. My high run in straight pool is 98 and I have run five racks in nine ball and eight ball several times. My high run at banks is ten. I have run eight and out many times in one pocket. Basically I am an above average player with a solid understanding of the game but far from world class.
My point about jump shots is that they require as much nuance as any other shot. Everything you said about kick shots applies to jump shots and especially to jump shots using the jump cue. I can take any rank beginner and teach them the diamond system in a few minutes and have them making three rail kick shots. I can take the same person and teach them the mirror system and have them hitting just about any one rail kick shot in a matter of minutes. And they don't even need a particually good stroke to do the kick shots. In fact, they can perform most of them with a lousy bridge. I don't even have to do anything other than ascertain that they can propel the cueball in a straight line and hit a spot on the rail. (in fact Tom Rossman does this type of instruction at every exhibtion he does)
Conversely, if I took the very same beginner who I taught in minutes to make three rail and one rail kick shots using the sytems I mentioned, and hand him a jump cue he most likely would not be able to jump a ball using just the description of jump technique. The reason is that he would not have any idea how to hold the cue nor how to stroke it nor how to judge speed and spin. He would not know how hard to or soft to hit the ball nor whether to follow through or punch the ball.
More than likely I would have to first help this player to develop a proper stroke and follow through before he would be able to make the cueball jump over another ball legally. This exact scenario has been played out hundreds of times at my jump cue demonstrations/lessons over the past five years. Even good solid A players have come up to the booth and NOT been able to jump a ball using a jump cue until I corrected their stroke and explained the nuance.
Now, that same player who learned the diamond system a few minutes ago will of course NOT be able to adjust for the variables such as cloth speed, blocked pathways and so on UNLESS he develops the proper stroke technique and understanding that goes along with any system.
I can certainly see where it might sometimes appear as though a C player can jump as well as an A player when the jump cue is in use. The truth is though that the A player is a better judge of the nuances and better able to execute the shot with the correct speed/spin and therfore is more likely to get a desireable result than the C player. Just because once in a while I hit a three rail kick shot with perfect accuracy in no way equates me with Efren or Torbjorn Blohmdahl, (with whom I have played on pool leagues with BTW - shameless name drop). A book or tape on kicking only gives one the knowledge of how to do it not the ability. A jump cue only gives one the possibility to jump a ball not the ability to do so. In conclusion, I am sticking to my original statement that both the jump shot and the kick shot require a high degree of skill to master and that they are equal in difficulty.
I will be more than happy to demonstrate this at the Midwest Expo in October. Look me up in the FURY booth.
John