I have long been suspicious that most jammers are not newbies, but actual, serious DXers. A**holes to be sure, but serious DXers none the less.
Some of them, on SSB especially, make very accurate comments -- too accurate -- about where the DX is listening, for instance. There are other clues of that sort.
They apparently subscribe to the idea of "if I have mine, and suffered for it, I'll make damn sure you do, too, because that is part of the game." Or, they just like the sound of their own voice or keyer, take your pick.
So, this may not be "ham radio running downhill" because of X, Y, and Z, but a**holes that have been among us all along.