Years ago when I started making promotion for sake, the main "enemy" was the wrong image of the brew caused by the piping hot sake served in all too many restaurants, not only abroad, but also in Japan. For this hot sake, the cheapest kind of regular sake was used, the one with additions of sugar and flavorings, which after imbibing may cause a headache the next day - so a beverage not really successful in winning friends for sake. In Japan, I mostly used to meet this beverage at bonenkai (year end parties) when restaurants try to keep prices as low as possible and party goers drink as much as possible to steep the past year in forgetfulness... I have heard this stuff designated as "jet fuel" and that is a very apt evaluation!
[Sake warmer (yukanki) made from Shigaraki ware. Hot water is poured into the large pot, then the tokkuri is placed in it until the sake has the right temperature. In this way, you can warm your sake at the table!]
So in order to position quality sake as something radically different from this fuel-type sake, we mainly promoted sake as a beverage that had to be drunk cold, and that was right as we were often dealing with ginjo-type sake. Serving cool is after all the right way for (most) ginjos and daiginjos, nigori sake, shiboritate, sparkling sake, unpasteurized or half-pasteurized sake, and so on. But there is also sake which is delicious when drunk warm!

These are in the first place junmai sakes (junmai-shu); and also honjoz...