A couple of reasons
Primarily because there are many conflicts between what he said, and what others said. Too much of what he said has either been discredited, exposed as plagiarism, or been wildly inaccurate.
Also, his determination at times had many aspects of zealotry to it, and that always concerns me in someone with a great deal of power, be it personal, political or financial.
The fact that he has gone out of his way to imply that he helped capture Eichmann, while Isser Harel who headed the team that caught him has always denied this. He has refuted pretty much all of Wiesenthal's statements in that regard.
"All the information supplied by Wiesenthal before and in anticipation of the [Eichmann] operation was utterly worthless, and sometimes even misleading and of negative value."
which is a cite from the nov 12, 1993 issue of Forward
He has either lied, or misremembered details about Mengele, Eichmann Frank Walus and others. He has claimed that people were killed in camps who later turned out alive, and claimed a former campmate saw mengele, when the woman in question had never been interred.
I don't deny that he did good during his work, but his track record leaves me with a lot of doubt.
Edited by Godeskian, 20 September 2005 - 09:04 AM.