"Holocaust" was not in general use at the time to describe the mass murder of Jews by the Nazis and is not used in their own language by Jews themselves today. It is a superfluous, post facto introduction to the English language.
I agree absolutely. I do not use the word "Holocaust" myself, and even some Jewish historians such as Walter Laqueur have labelled the use of that word to denote the mass killing of Jews by the German Government during the Second World War as "singularly inappropriate".
The reason why they consider it inappropriate is because the first use in Jewish literature of that word was in the Greek translation of the Hebrew Bible, the Septuagint, where it was used to denote a "burnt offering" made to Yahveh, ie it had a religious or ritualistic connotation, the idea of placating Yahveh for having sinned against him. Accordingly, for those historians, the use of a term suggesting a "burnt offering" implies that the mass killing of Jews was a sort of punishment for some offence committed against Yahveh, a belief that is in fact held by some Jewish religious extremist sects, for whom the offence was Jewish secularism. Since the mass killing was not perpetrated for a religious reason, ie for having failed to uphold the Judaic law and to serve Yahveh properly, but rather for purely political reasons, the use of the word "Holocaust" to denote it is inappropriate and misleading.
The Hebrew word used to denote the mass killing, "Shoah", does not have any connotation of a sacrifice to Yahveh; it simply means "catastrophe" or "destruction". The word used in Yiddish accounts of the killing, "Churbn", also just means "destruction" and has no religious connotation. It is noteworthy that the earliest Israeli publications in English about the mass killing of Jews during the Second World War always used the word "catastrophe" to denote it, ie a literal translation of "Shoah".
It was not the Israeli Government that decided to use the word "holocaust" as a name for the mass killing of European Jewry, but rather Jewish organisations in the United States, and there can be little doubt that the reason for choosing that name was precisely because of its prime connotation in Jewish religious literature, namely that of "burnt offering". The fact that the name "Holocaust" has gained general acceptance, and almost the nature of a trademark, not only in English but also in many other languages, reflects the cultural dominance of United States Jewry over the other centre of the Jewish people located in Israel.