Well, the non-fictional relevance of the quote is that it represents the views of the author, who may or may not be basing his opinion on fictional evidence.

Also, you are suggesting that Hermione was convinced that killing Draco was the right thing to do. That's probably incorrect: she was described as saying she stunned Draco in a "fit of anger" and felt horrible afterward.

(The only reason I say "probably" is because the court Legilimens did, in fact, find her fantasizing about how she thought Draco might cause harm to her or Harry.)

Yeah, you're probably right about this.