I'm going to give you the benefit of doubt and assume that you are in fact reacting to what you see as a censorship of discussion by tabooing the whole subject. My point with the Orwell quote is that in most cases of European "denial," it was being promoted almost exclusively by Nazi/Fascist sympathizers. Hence the labeling and stigmatization of "holocaust deniers," which incidentally was initiated mostly by the Germans of the 1950s, disgusted by the sins of their fathers.

In the 1960s Palestinians adopted a skeptical-conspiracy "denial" that was part of their conflict with Zionism. IE the holocaust myth was fabricated as an excuse for Zionist colonialism. The current chairman of the PA, for example wrote his doctoral thesis on the subject. Over about 20 years this simultaneously percolated into what has become semi-religious beliefs in the Muslim world on one hand and backed away from by its original proponents as their evidence was strongly and insistently refuted in academia. The aforementioned chairman, for example, no longer promotes these ideas. In the instances that it has merged with religion it has also adopted various medieval anti-jewish mythology and/or 19th century Czarist propaganda. Various Muslim brotherhood affiliates streams, for example, believe in the Czarist "Protocols of the Elders of Zion" document.

This is why I noted European denial separately. A lot of the modern leftist skeptics are influenced by this wave (rather than the earlier fascist one).