Why do so many Christians attack Fred Phelps or Harold Camping?

I can see what you're saying. Both just have their own interpretations of the Bible, but religions scoff at them. Do I think they're right? HA, no, I'm one of the ones who thinks they're deluded, but they do bring support from their ancient book for everything... Many Christians just don't want people to see what they are really supposed to be doing, so of course they'll attack Phelps and Camping.