I’m not sure I agree with your base premise; if we go back 50 years I don’t think there’s a greater diversity of thought or opinion, because the social circles we move in (in say the 70s) are very local, and our opportunities for discovering new ideas are extremely narrowband and require much more work (limited access to information in the form of newspapers, magazines, tv, or thru travel to different areas). As far as vintage and craftsmanship goes, a “vintage” item in the 70s is more likely to be individually crafted vs mass manufactured, but is still accorded value based on nostalgia or novelty. Mass manufactured items still become vintage because the number of them dwindles as style or technology trends dictate that they should be thrown away or replaced with something new. In many cases those mass manufactured items are still imbued with craftsmanship and design novelty.