The Lancet is one of the most rigorous academic medical journals and everything that gets published in it has to meet certain standards, depending upon the type of article. Medical and scientific journals' 'letters pages' are different from letters pages in newspapers and magazines - the pieces published there are still reviewed and held to certain standards. While the piece that is the focus of this thread is not a fully-completed S-tier research project, it is still more deserving of consideration and reflection than most of the media articles published and held up as 'fact', which go through considerably less scrutiny pre-publication.
This is another example of double standards coming into play against Palestinians and majority-Muslim demographics. When a journalist with a track record of political bias writes an opinion piece that is critical or minimising of Palestinians and Muslims, it is held up as something which must be given weight and value, respect for it is demanded, and it is cited as evidence even when it's just someone's opinion. When professionals with relevant expertise write a piece which is published in a highly respected academic journal, but that piece does not minimise casualties and in fact extrapolates that casualties could end up being considerably higher than what is generally being discussed in the media, it is subjected to a much greater degree of criticism and efforts to dismiss it. It is also very telling that people (in general, not in relation to any particular people) can read published articles about horrendous death tolls and suffering, but express very little (if any) sadness or compassion for the population affected and instead jump straight to being 'experts' in critical appraisal - it speaks volumes about how certain populations have successfully been de-humanised in the eyes of many, that people no longer feel or feel the need to express empathy for those populations in the same way as they would for other populations.