The only thing that can kill pinball is not passing on the knowledge and the passion.
Video games in the early 80's almost killed pinball as a pastime
Hand held video games did the same in the 2000's
Pinballs from the 40's and 50's can still be restored and owned. Not even the mob and gangster's in Chicago finished off the silver ball.
The NIB availability for home owners is a relatively new enterprise, one Stern took years to realized and then capitalize on. The prices of NIB machines is appalling, and I would never pay $9,000 for a new pinball machine, especially a low quality game, or a game that takes 6 years to produce. While the demand is high, manufacturers can set the price. But I think the NIB experience will be killed off as manufacturers take short cuts to save on production.
Personally, I've never shown an inclination to buy NIB. Since I was fortunate enough to watch machines being unboxed in pinball's Golden Age, I don't see myself buying a NIB when I can buy 4 decent titles or 10 projects for the same price.
Manufacturers need to understand the market. If Stern and JPP closed their doors tomorrow due to killing the NIB market it would not surprise me at all. But it won't kill off pinball. Not even close.