There's a lot of retro arcades opening up. I don't think it'll ever be like what it once was but I'm 25 and all my friends have a blast on my pins, even the ones who've never seen one in real life before. Yeah they may drop in popularity but I don't think it's as bleak as your making it out to be. Prices will drop but there will still be demand from collectors especially if they were cheaper. I know many people in their early 20s who tell me they'd love to own a pin if it were cheaper. If someone can lower production costs that's where I really see a rebirth happening.
Kids will still enjoy pinball if their exposed to it, it's just in this day and age most route machines are in horrible condition

while i agree i have a feeling that more kids today are being exposed to pins through collectors then kids who are now in their teen years were when they were growing up. I know when I was growing up mainly in the late 90's I can only think of maybe 2 locations that had pins at that time, when I was in my late teens I started seeing alternative/punk clubs start having a pin around and now most of the trendy hipster pubs and clubs have at least one pin in them

If the market starts dropping and prices get cheap enough you'll see LOTS more people under 30 buying a pin, maybe it won't be as large a variety of pins around though as I don't know if this kind of buyer is looking to buy multiple pins

ding ding ding

I really think the lower end pins are rising in price because that's what the new comers can afford.

I'm considering trying to add an RCT to my collection next to go with my RBION and WW in the lawlor collection I seem to be acquiring lol, was a fan of the RCT games growing up and I want something with more ramp shots that won't send me broke.