I still think he had something to do with Ramonas death
By the time Ramona died (2006), he was already way over the hill IMO.
His golden years were the second half of the nineties. I know his son’s problems upset him, but it seemed to me that 9/11 embittered him even more, at least as it came through on the radio.
After 9/11, he no longer had that tongue-in-cheek twinkle in his eye which was so much a part of the charm of the show before.
Maybe it was just that 9/11 coincided with his son’s problems, and the change in Art was unrelated to 9/11 itself. But for a man whose show was based on conspiracy theories, it was striking that he would become upset at the mere mention of 9/11 conspiracy theories, in contrast to his generally open-minded attitude before.