Mishima is probably such a striking figure to those into noise and, by extension, its aesthetics is because Mishima's literary practice is based upon principles that more or less parallel topics, either directly or tangentially, that are heavily explored in noise: misanthropy; isolation; the cold, detached practice of dispassion espoused in the Chief's teaching in The Sailor and, although unspoken of as such, unconsciously practiced by most if not all of his protagonists; destruction, usually committed based upon the protagonist's search for and failure to find beauty, as well as his own warped views of beauty; internalization; etc.
Japanese literature has a style that is very sparse, terse and rigid. Entire chapters could take place in one's own internal space, all besides what is in one's own head being of no consequence.
Also, his supreme commitment and tragic resolution of his devotion to a cause makes him a more emblematic figure than one who died as quietly as he wrote.
Also, let's be honest: the guy organized a militia, staged a coup, albeit a failed one, and disembowled himself after having stated his demands.
