That last little tidbit is the hard part to find as all the gee-whiz online information about these hugely popular shows conveniently ignores who paid for them.
Anyway.... My point is that the early '70's date exactly lines up with the end of the big Art-Tech shows which were, 1) Funded by large corporations -- Pepsi, Phillips, Bell Labs, AMC, etc; and, 2) Contained new work that was research oriented -- rather than greatest hits from the past. So, what happened was that our corporate masters realized that they could get much more bang/buck out of old dead artists than they could from work that better aligned with their scientific and engineering pursuits. And PFFFTT went the collaboratory milieu.
Fortunately, I Am a Sensitive Artist, so I don't actually have to support this hypothesis with actual data...
In Other NewsSomething has changed about the Lazzaroni Amaretti Cookie wrappers. They no longer fly. The paper doesn't form the ash chimney as shown in the video. It appears that it is not just me as I've found a number of complaints online dating from 2008. But no explanation. I would have at least expected the box to have a warning and liability disclaimer about lighting anything on fire.
The only constant is change. For the worse.