Aaaaaaaaaaaaaaaargh! (s'not meant to be an argumentative post)
showing off plays a large part in that shift in emphasis
The skydiving community has instructors who offer advanced canopy flying but unfortunately not a lot take the opportunity so they operate on the basis of they dont know what they dont know and hence the inevitable accidents.
seeing as they're already aviators, the skill set is mostly there to begin with
A square is a low performance glider with a unique set of handling characteristics which take experience to master. A reading of the United States Parachute Association "Skydivers Information Manual" (available online) will persuade any reasonable reader that you dont just strap on a square and go jump. The "Emergencies" section is quite formidable also.
RIP Martin Siddell, 52, a British Airways 777 Captain was parachuting at Skydive City in Zephyrhills, Florida, about 25 miles north east of Tampa, when turbulence collapsed his parachute at a height of 150 feet.
Attempts were made to revive him but he died at the scene.
PS Anybody who thinks its not fun should give it a try. Best to be had (with pants on or off)