... on SN?
Blame it on the internet that's provided a more level playing field for views and opinions from media or groups or individuals.
Have a view as crazy as you can think, start a Facebook group, or post a Youtube video or an opinion piece in some online media and a few weeks latter there will be a following with people regurgitating the same view as fact.
Worst still is most people now ignore mainstream media and follow media, groups etc they like which creates a bubble in which their views are reconfirmed by others, and on it grows.
People always complain about murdoch media etc but really thats the least of anyones problems when you have people sourcing views, news, opinions online from truely dodgy sources.
....... or be rich enough to spend hundreds of millions of dollars to discredit valid science so you can sell more fossil fuels.
My two cents worth -
I see the following as being tied up in denialism.
Straight up lies eg. lying about climate change so as to continue business as usual.
Fear for the state of the world eg. environmental crises leading to a rejection of science, because it's seen as the root of problems
Increasing personal liberalism leading to libertarianism wherein anyone can have their own set of 'truths'
Throw into the mix - fashion, peer pressure, and a growing apologist culture which increasingly sees the questioning of forms of denialism as being narrow-minded bullying.