Yes, Krebs' does his own research, but he also has hundreds of security researchers and contacts that provide him info, many of those are insiders. In his book Spam Nation, he even goes to Russia to visit a crime boss to ask tough questions. This isn't some cyberstalker.
Krebs is a better researcher than most, so I tend to trust his doxx. Most of the info he publishes is already public (poor opsec) and he is more thorogh than Reddit. Can he be wrong? Sure..... should he doxx? I don't know, that's an ethics question.. but if he's wrong on this, I'm sure Brian will reconsider that in the future