Thing is, some of the stuff that these right wing conspiracists are on about is real.
There
was a "long march through the institutions" which aimed at a left wing cultural hegemony. If you pick a university lecturer at random they are quite likely to be left wing or liberal.
LGBT+ people
have engaged in campaigning around normalising homosexuality etc.
And to some extent these have been victories. (In other areas less so - why was higher education such fertile ground for this stuff in a way that factories, warehouses and call centres don't seem to have been?)
But obviously conspiracy theory is the wrong way to look at this (perhaps with the exception of things like the Living Marxism/Spiked cult:
http://www.lobbywatch.org/profile1.asp?PrId=78 )
What these things are, are social movements. In the same way that the alt-right is a social movement which is trying to establish its own cultural hegemony.