The answer is that the people involved live in a bubble, almost entirely surrounded by like-minded people and hence having little or no contact with alternative views of the world. Republican voters who watched Fox News were genuinely amazed by the recent election result - primarily because they had accepted the Fox News opinion polls as accurate. On Election Night even when it was clear to almost everybody else that their side had lost they remained in denial.It is pretty much the same with most, if not all, of the non-mainstream Protestant splinter groups. Members find that their friendship groups, their social life and even their political views have foundations in their particular brand of religion. You might expect that most Christians of all denominations would be politically to the left of centre and heavily into the dignity of man and human rights. In practice many stalwarts of these smaller fringe churches are almost unendurably pompous - appearing to outsiders as almost totally indifferent to the bigger picture.
Nothing is too much trouble for them when it comes to helping member of their own tiny clique but when it comes to the “Big Society” far too many of them simply do not want to get involved. Or if they do want to get involved they think that they should wield influence out of all proportion to their tiny numbers. To them democracy isn’t about the counting of heads but the weighing of heads - with their heads counting for vastly more than those “poor unfortunates” existing outside their personal bubble.