I think the 'NiB' craze is relatively new in this hobby (comparatively). This is what is starting to turn people sour. Between the seemingly endless increase in prices, the flippers grabbing up what they can, and the occasional scam and/or poor quality it all starts to add up in a negative way.
As has been mentioned though, you dont need to start with a NiB. I've owned machines since the 90's and I just bought my first NiB 2 years ago. Here's the kicker. I did this AFTER having paid off my mortgage, my vehicles, basically no debt other than monthly bills. Some of you in your 20's/30's...you're suffering from the 'gotta have everything now' syndrome due to the crazy increase of interest in pinball.
Even when I did that, I said never again because even if you love the game, the value isn't there. Of course, then I proceeded to buy 2 more hah. I get where if you are expected to pay 4k+ for a 20-30 year old game, that paying 6k for a brand new game may seem like it makes more sense. Especially since all the new games are actual licensed properties that are popular. The trick really is to plan to rotate them out if you plan to keep wanting everything that comes out. I've just not gotten tired of anything enough to bother.