A lot of valid points are being raised here. I actually don't think is as bad as what it seems though. Sure, it is never going to get back to the heady days of the Coors/and what we had in the UK - Kirtons Jump Classic etc in the 80s, where you had hundreds lining the banks watching, but with the advent of TWBC putting such fantastic coverage of tournaments - online- in slalom and now tricks and a bit of jump - I think that is changing a bit. In the UK we have quite a few sites where beginners can learn for really a minimal cost, pay as you ski - all equipment provided, with good enthusiastic coaches. My old site did that, we must have taught hundreds in the noughties - Wakeboard and skiing (mainly wakeboarding then). There are still plenty of busy sites in UK still doing this, My old ski club at Ringwood and Chris Mullins (CJM) near Heathrow. There are still these sites where it is easy to get access. What these sites are up against, amongst other things, is the cost of insurance, this is the thing that will make it harder to make it pay. It is not easy to run a site, I doubt if it would make you a millionaire, probably better to start off as one.
I tell you what I found interesting though. I have skied pretty much all my life and 3 of my daughters also have done a bit, being a partner in a watersports centre helped that I'm sure. I don't ski as much these days - done a few (slalom) competitions locally fairly recently (in the UK) and my youngest daughter, the 4th one, has been along and not seemed that interested in having a go. She is now 15, not particularly sporty but when I was watching the TWBC trick competition the other week, she came across to where I was watching the event, watched for a while and after remarked that she'd like to have a go/learn when it got warmer. Before she saw the trick event, she couldn't have cared less about waterskiing.
There are lots of different things that can get people in. Once you are in it is all about the personal challenge at every level. Slalom is a very easy discipline to measure your achievements, especially in the early stages.