Is High Power in decline? Hard to tell... over the years, the hobby has eat up mfg's and spits them out. Ask anyone who has tried to start up a small business on the side to support the hobby they love. Most will close doors after a couple years and are never heard from again. Honestly, once the numbers were posted, I did not realize that the rocketry community was so small... I mean, I knew we were not NRA big, but I assumed there were more than what was posted. I believe it is still a cost to fun ratio; I know of one individual who got me interested in high power and research, and he left to pursue RC planes... his reasoning was he was having more fun slope and sailplane soaring and flying RC wings... most of the outfits he builds cost less than the price of an M-class reload, and he can fly for years... YEARS, barring any crashes, on any one of those vehicles... His reasoning for leaving was that he reached a point that the cost / fun ratio was that he was not enjoying the hobby any more... secondly, his money was best spent elsewhere. I tried to follow him into the RC world, but grew bored of crashing, so returned to rocketry... lord I have left the hobby so many times that it is becoming a seasonal turn for me. Hopefully I will find something that sticks.
Is it on the rise? The two local clubs have so many new fliers that I am lost around the clubs anymore... there are still a number of die-hard veterans, but the clubs have turned membership at least once in the last 4+ years. I find it kind of interesting that some of the seasonal vets supplement their high power fun with doing pyrotechnic shows during the July 4th and Dec 31/Jan1 holidays... I got to help out one of those times; I was on a four man crew that ignited 6" shells... professional grade fireworks look so different when you are under them when they go off and rain debris all over your face...
Maybe the hobby is waiting for the "next big thing" to hit the market... when I first returned to the hobby in 1997 HyperTEK was hitting the scene pretty hard, and hybrid propulsion bloomed with a number of different motors coming to market. Hybrids are all but gone now, and everyone is back to flying APCP whose prices continue to sky-rocket (pun intended). Like "Cheap Access to Space (CATS), many of us are looking for "Cheap Access to High Power (CAHP... acronym does not work)...