Putting aside the murder being covered up, Claudius seems a capable king, Gertrude a noble queen, Ophelia a treasure of sweetness, Polonius a tedious but not evil counsellor, Laertes a generic young man.  Hamlet pulls them all into death.
 

I haven't read Kerrigan's book, so I don't know whether he intends any irony at all in the first condition, but what a colossal bracketing that is!   Aside from its suggestion that the murder can be neatly swept behind an arras without its being symptomatic of any larger problem, as a summary, it's weirdly illogical: Kerrigan/Knight begins by asking us to imagine the play without its most significant death, and then blames Hamlet for returning us to that death.

And then, too, there's just the insidiousness of such a bland and blind reading: as if these character's words (and for that matter, real people's) words could be neatly extricated from the creeping rot of Denmark.  It's almost like assigning someone who's an extremely poor judge of character to be a parole officer for a convicted killer: [blinking] "Putting aside the murder, he seems like such a nice boy."