Yeah , you ignored the rest of the sentence that you half quoted.
Yup, did that for emphasis, to address an issue rather than to address your sentence. Sorry!
I think its fair to say that any normal klingon would consider this solution to be worse than death.
Why should that be of any concern? It's not punishment
that Worf is imposing on Kurn. It is aid
. The point is to liberate Kurn of the burden of having to live a wronged life. Killing him is one way to end his life and let him try out another one (if one believes in life after death, that is). Killing his personality and giving him a new one is another. Nobody is concerned about old Kurn's welfare or feelings, because old Kurn is spoiled goods. But there may now be a new Kurn in this life or the next. And Kurn might actually appreciate the former prospect, the technical impossibility of such appreciation aside.
Granted, old-fashioned Klingons might balk. But they balk at all modern nonsense such as bandages or ranged weapons. There are plenty of modern Klingons around.