I must disagree... Arthur is still on the air, and It always makes me Laugh (yesterday and today had numerous jokes about Indian Jones and TinTin comics, and I bet I was the only one who'd get the latter).
but the unrequited crap like Barney, Jay Jay, etc. are probably only on for merchandising reasons. i was so shocked to see that Barney had a come back after the 1998 disaster, "Barney's Great Adventure" I still see that merchandise in numerous toy stores marked down to the lowest they can go, gathering dust...