Kurn was suicidal. He wanted Worf to kill him; failing that, plan B was to kill himself by any means necessary.
Last time I checked, assisted suicide is illegal even when the victim suffers from an incurable, painful disease.
This is NOT a morally 'clean' thing to do. Quite the opposite.
Now - finding a way for your brother to live instead of snuffing him with a dagger is morally reprehensible?
I disagree. What Kurn wanted was Mauk-to'Vor, an honorable Klingon death to make up for the disgrace upon the House of Mogh and get into Stovokor, which his brother could give him -- all within the confines of Klingon customs, morals, and laws. Where Worf screwed up the first time was not taking a leave of absence to do it elsewhere either by ritual or by fighting an enemy as warriors. He should never have considered performing Mauk-to'Vor on Deep Space Nine.
Then, to compound the problem more, Worf ends up making his brother betray the Empire, leading to Kurn killing a Klingon warrior for doing his duty in service to the Empire. Yes, Kurn made his choices, but at least before this, Kurn could at least say he had some honor
if only to himself. Yes, he was in disgrace before, but at least that wasn't his own doing. Now his "dishonor is complete."
What Worf does next is strip him of his identity and memories of being a proud Klingon warrior. Oh .. and Julian goes along with it without Kurn's permission.
As far as this episode goes - -- Fuck Worf.
"Kurn, Son of Mogh" died without honor and there won't be any songs about his heroic battle with Julian's engram scrambler.
--and that's why the ending wasn't awful. It made me angry at Worf.