I fly F3C helicopters and we are ALL asking the same question; "Why aren't people choosing to fly contests anymore?" When I flew my first heli-NATS in '93 there were 89 pilots in the 4 classes. In 2005 there were less than half that. We have been brainstorming to come up with good reasons and have several ideas.
a) The young fliers of today are members of the "right freakin' now" generation. Anything that they cannot succeed at in 5 minutes gets cast aside.
b) The models, et al, cost too much.
c) There are professionals doing this and you cannot compete with someone that does it full time.
d) They'd rather 3D where the "WOW" factor is high and they get instant attention and noone can say they did it "wrong."
e) It takes too much time to practice and there are too many other things to do.
f) Flyers today are members of the "Harley" generation, that is, they want to do THEIR thing and have no interest in how anyone else does it and don't care what you think about it.
g) Gas is too high.
You can make good arguments for AND against each one of those and I suspect there may be a grain of truth in each but none is the total answer. The places I see strong contest groups are where there is a strong leader who contests and brings his buds with him. Is there an answer? I dunno but I suspect it'll get worse before it gets better.
Gordie