I think the difference of that with the left wing conspiracy theories, it's usually some meek old hippy who believes in UFO's and wants to speak truth to power. Didn't Dennis Kuccinich say that he saw a UFO?
Whereas in the right, well, the conspiracies they see are all manifestations of some super ****ed psychological problems common to frustrated young men in a world where success with women and economic prosperity evade them, and this brings out all these demons lurking in the primitive human psyche. In this ways the alt. right is not so much a fundamentally racist movement (though it is that too), but a primitive one (kind of like the Nazis).
I have an alt right friend who speaks kindly of Ted Kaczynski and his concept of 'oversocialization', where modernity and social norms themselves are in fact to blame for denying young men from realizing their full natural potential, so that his various right wing theories are actually a special case of a general rebellion against mainstream society itself.
If the alt. right comes along, then, and lets him blame 'leftists' and communists and cucks for pretty much everything going wrong with the world as seen through the eyes of a frustrated young man, it's pretty much a shoe in.
It's a right wing movement related to mainstream conservativism simply because Rush Limbaugh and Fox News have also been blaming leftists and communists for everything under the sun, albeit in a less unabashedly primitive way, for decades.