SUCH things as subtlety and ambiguity - and thus human nature - are not the friends of moralisers. For them, the world is more easily understood in binary terms, every complexity reduced to just two options, of which their favourite is "good" or "bad". Rarely, however, is this actually the case. Choices are thus more easily made for moralisers - in any situation they have only two and who would chose to be bad ? Perhaps, then, it is fair to say moralisers only ever have one choice. And that is no choice at all.
Any prospect that this sort of fundamentalist thinking might lead to actual fundamentalism depends on how well set it is. There is a difference between believing one has only two choices and insisting this to be the case. The former can be unlearnt, as usually it is the result of little more than ignorance. The latter is less easily countered. Education and, with it, knowledge, helps. With understanding comes complexity and, with wisdom, an appreciation of it. When binary thinking is common and pervasive, curiously, it becomes harder to identify. So captivated are people by whichever false choice preoccupies the public mind, the possibility that a third or fourth option might exist simply never occurs to anyone; they are too busy reinforcing their particular trench.
The great appeal of binary thinking is its simplicity and those forums that lend themselves to simplicity attract and reward moralisers. The more such platforms, the more moralising. All of which is to the detriment of real moral dilemmas because, in that rare situation when a call does actually have to be made between something good and something bad, people are none the wiser. It represents merely another opportunity to knuckle down and fight, and whatever side they choose, it is simply a response to that desire.