sorry, also not true. warm sake has a depth that cold sake often lacks. it is completely dependent on the style and flavor profile. to say that the vast majority are better cold just shows that you really don't know sake.
I'm not going to get into an argument over taste, but I was glancing around the web to see whether I "really don't know sake". The "vast majority" of this site's top 100 seem to be recommended to be consumed on the colder side of spectrum. Also, while you may have access to some good stuff that is fine warm, in my experience (particularly in the US), the warm sake served in Japanese restaurants tend to be of a lower grade and an overall worse experience. If someone is interested in getting to know sake, I recommend that they start out buying good stuff in a specialty store and drinking it cold, as overheating it (which often happens in restaurants) tends to kill the taste and make sake into a one-note alcoholic beverage. YMMV.