I think that was in 1983, Bob's last year as champ, where he became one of Dave and his readers favorite whipping boys. Many things contributed to it, but basically Bob and WWF in general were looked at as stale and "lame" compared to the more exciting territories of the time, like Mid Atlantic and World Class and wrestlers like Flair, the Japanese stars, etc. 83 was also when Bob became noticeably smaller due to a change in workout routine and adopted the buzz cut and later singlet, making him look pretty uncool, especially compared to someone like Flair. Also, the booking of Bob in 83 was uninspired, with several repeat challengers, like Ivan Koloff, Slaughter, the Samoans, George Steele, Muraco, etc., which did him no favors, and I think Dave also started to push the whole "the crowds turned on Bob and he stopped drawing" talking point at this time. I think a lot of hardcore fans were also clamoring for Snuka as champ, or at least someone different, as Bob had been on top for 5 years.
Someone with access to the 83 Observers would be able to explain it better.