The truth is that there is enough blame to go around in almost any circle.
However, due to many UC's not believing others are even saved unless they're as "holy" as they are, it seems that more fall into that category than others.
It is a "theosophical" viewpoint that they can't concede, for if they do, their whole house of cards comes crashing down and then they must conclude that one can indeed be saved, holy and acceptable and pleasing to God without their strict viewpoint.