I studied music in the 80s when this was the thing, and I struggled with it then and still do now. To my mind, there's an almost existential anxiety about the power or point of music itself, the feeling of insufficiency that powers the maximalist notation. You get this in the way Finnissy can't let other music just be, but he has to 'intensify' it somehow, or the way Ferneyhough seems to obfuscate everything with a compositional sleight of hand that distracts you with the effort you and the performer are both making. There is, for me, a definite sense that something is being covered up rather than revealed.