For the record, and speaking only for myself, I only said the method does not appeal to me for cooking something as simple as steak, but that those to whom it DOES appeal should take care to follow specific food safety protocols as advised by their own experts in the field.
I was a County "Food Cop", so my own squeamishness about long term holding of foods between 40 and 140 degrees is professionally derived. It isn't specific to airless (sous vide) cooking. Bacterial growth during long term holding of certain foods in that temp range is well understood, and manageable if adherence to simple time lapse/cooling/serving precautions are adhered to.
I would add, though, that with sous vide the extra dimension of the use of vacuum packaging does elevate my concerns. Botulism is one of the deadlier forms of food poisoning, and while the spores themselves are everywhere, growth and toxicity is strictly dependent on their spending enough time at mild temperatures in an airless environment. Such as a vacuum bag.