Gord, to me it's not surprising. To people who were not around in the 60s, it's very hard to comprehend just how big UNCLE was. It kicked off the whole spy craze on TV in the 60s which soon glutted the airwaves. In addition, the show was hugely popular with teens and younger viewers. Hard as it is to believe now, networks didn't really give a shit about attracting younger viewers then, they wanted older viewers who actually had money to spend. So, shows that had great ratings with the younger crowd (UNCLE, Star Trek, The Monkees, Gidget, etc.) were not kept on the air as they did not bring in enough total numbers and the audience they did bring were not what the networks wanted. There was no such thing as demographics then, just total viewers.
Unfortunately, UNCLE suffered in the early 70s in syndication when the parents groups went after violent TV shows. UNCLE was one of the worst offenders and suffered accordingly. Of course now it's nothing to see people killed when a lot of shows show the corpses and what they look like. But at the time, UNCLE was virtually wiped out of the airwaves and so you really had to be around in the 60s to know what a neat show this was and how popular and influencial it was.