To a degree I do have some sympathy with the religious fundamentalist and literalist. ( Not much we are basically opposites. ) But when they look at moderate religion, especially cults, like the, so called, spiritual and metaphorical views of theism, Christian culture, and corporate religion for profit, then they see quite rightly, that it is, shallow, narcissistic, dishonestly cherry picking, manipulative, self serving, and corrupt, so that their moral instincts give them a visceral disgust at the very thought of it.
Their mistake is in thinking that more, and more extreme religion, not less or no religion, is a better answer.
I don't agree that moderate religious sects are more "shallow, narcissistic, dishonestly cherry picking, manipulative, self serving, and corrupt" than fundamentalist ones. I think it's the other way around.
Could be, in fact almost certainly to some degree so, but if the fundamentalists see the moderates as all of those things, then they are not wrong either. Moderate religion helps the fundies in three ways, its failings make them more certain of their extreme views, it renders all religion respectable, and it creates the environment in which they can swim and look for support. Both negative and positive assistance.
@Fernapple I have maintained for a long time that moderate religionists are enablers of their more fanatical brethren.
Around the world, fundamentalist sects are the most dangerous, the most violent, the most determined to gain power, and the most willing to twist and cherry pick their own creed to suit that end. In the USA, we find nominal Catholics and Protestants among the ranks of the Christian nationalists, but the vast majority of them are Evangelical Christians. They are our own, home grown, American Taliban.