I'd also throw in that the Australian experience is instructive: since professionalism the pathways to Test level have been getting narrower, and things like the schools arena are shrinking alarmingly. The change in demographic means Saturday sport is getting gradually overtaken by work, there is less money to go around, and you've got a shrinking grassroots scene where guys just can't/won't play because if they get injured, their lives are fucked.
Talking to Red Beard, the situation around Waikato sounds similar - if you're a kid who is good at rugby, the local Big Rugby School will hoover you up, and warehouse you so another Big Rugby School doesn't get there first. You might make the First XV or not, but you're in the frame for a provincial or even fully professional contract. If you don't get that contract, well you're more likely to leave the sport forever as an active participant, whether playing volunteering, refereeing etc.
See it here all the time. So really the proportion of casual fans is growing, and all they care about is winning. If you're not doing that, where to?