Camping sucked a lot of people in. I was one of his listeners in the early 90’s. My warning bells went off exactly when it did for these people - he started telling people to leave their locals churches, as they were all corrupt, like the Mormons did.
I didn’t know enough to understand exactly what Camping was doing wrong, but I do owe him in this - because of him, I started studying Hermaneutics, which is the science of biblicat interpretation. I started listening to the Walter Martin teaching, and by the end of the first half hour I was stunned to find how many rules Camping had broken.
By the way, here is some streaming courses in it:
http://www.blueletterbible.org/audio_video/comm_topic.cfm?AuthorID=35&commInfo=62&GroupID=0
Right or wrong? Good or Evil?
I cannot say.
What I can say is that this may have helped some of those who got caught up in this. Maybe it has made them better Christians.