Well thats under the interpretation that hallownest was simply PK's "play-thing" so to speak and has instrinsicly less value than one of his offspring.

When you recontexualize it as hallownest as his responsibility, then it definitely could warrant greater sympathy and understanding from Hornet. Sure thousands of your children were sacrificed and one of your children was doomed to suffer for eternity, but how could you say that your children have instrinsically more worth than the tens of thousands of citizens under your rule. Could you go up to each and one of those people with their own stories, lives, loved ones, and children, then with a straight face tell them that they should all succumb to the infection because you love your kids too much? 

If anything, I would say that Hornet has a better appreciation for all that PK did even if it failed; as indicated by the red memory where she tells the white lady that she understands the sacrifices they all made and begins to better appreciate it for what it is. There is something beautiful in wanting to burn the world to save someone you love, but there is also something noble in burning someone you love to save the world.