A phrase used specifically to indicate your dismissal of a
particular statement, event, or viewpoint.
It is used to categorize something as noise, primarily. As if something is not even valid enough to be considered having a form. In
reference to a viewpoint, it would indicate it's validity being on par with random noise.
As anyone would, with some random noise blaring out of a speaker, "
fuck that", is expressive of a desire to mute it.