This is not a valid argument simply because the event literally has changed. It definitely used to feel more rock n roll in terms of how edgy it was. Heck, quite literally, I remember a time when dubstep wasn't even at HHN. Sadly, I bet more than half of this forum never got to see a Bill & Ted show. Or see the go-go dancers. Or go through the House of Horrors. Keep in mind, a lot of us still go to other haunts and have been going for decades and love them just as much or hated them (I went to Fright Fest ONCE 20 years and I don't think I would EVER go again based on how bad it was and how bad the videos make it still look). It's also reasonable that haunts go through up periods and down periods. I've been going to KSF for 25 years and I think it's currently in an up period that rivals how good it used to be in the early 2000s, especially with the return of The Hanging (especially now that I can SIT for it) and the maze quality they've been pushing out as of late.
Do SOME people change and no longer like HHN or these events? Absolutely. But that's not going to be the case, dare I say, in most cases. People age out of going to clubs/bars, but to compare this fairly, concerts are still popular with all ages depending on which band is playing.