He can voice that opinion because a he is correct the sources only say he was Jewish but not that this is relevant to this writings on racism  b it is established Wikipedia policy that we dont call out a persons background  be it racial religious or ethnic or other  unless it is pertinent to the topic as evidenced by reliable sources making that connection and c this is the consensus on this page   editors have told you that what you are proposing is not acceptable it is time for you to stop edit warring it back into the article