Ha, my first instinct is to disagree, and put up a fight for todays youth (me being one of them i still like to think!), but then i think you're probably right.
Depends how you define 'youth' - anything less than 20 I would say and I would agree with AndyF, it is too tough for the youth of today - a fair portion think that being active involves hand movement (no rude thoughts now please) changing channels and watching mind-numbing crap on tv or playing those computer game things where they think they are some kind of super-hero shooting the crap out of other people..
Not that i think declining numbers are an essentially bad thing though.
Others have said similar in this post - in some ways its not a bad thing, less people in the way no spaghetti on pitches, helps in conservation sense. But the less cavers there are the less of a voice we have in access issues, the lesser the numbers the less people know about it or understand it or have the chance to sample it - I've taken about 7 people from work caving plus a reasonable number of other novices over the years..
Are there fewer clubs about? Are there more armchair cavers in clubs?
Hard to say about club numbers - maybe someone has the answer, perhaps there are less uni-clubs about which was always a good source of new cavers..?
There are probably more armchair cavers about now than there used to be as the caving population ages and less and less fresh blood takes up the sport.
a) greater consumerism in sport (as in eveything else)
True, funding is generally given to sport that can be on show, provides good spectator ratings so that anyone providing money gets advertising.. Sports funding is mostly given to 'competetive sports' - as that is obviously a more deserving sector of sport :?
Let's face it, you never look "cool" when caving...
True, but how many people have taken an interest in what you're doing/where you're going etc when you've been dressed up in all that fancy gear. I've encountered a fair number of curious members of the public over the years!