While any rational person will appreciate the sentiment... I spent quite a few years wishing, and helping accomplish, the death of human beings. Completely different circumstances of course, but language is important and distinctions are sometimes VERY important.
I went human hunting at work every day for years, because it needed doing for reasons I don't need to justify or defend to anyone. I don't regret one day of it even though I'll have to live with it for the rest of my life. I don't think any of it was childish in any way.

Clarifications aside, you're of course correct. In spite of the massive long-term impacts a radical supreme court justice can have (from any point of the political/social spectrum), wishing one dead comes across as a wish for the destruction of the entire concept of American lawful society. In spite of supreme court decisions that I think are utterly destructive to the US and against the constitution that those judges are supposed to uphold, I strongly prefer our current system to having a king, religious oligarchy, military "protectorship", etc etc.

ISIS has a court system too, and I prefer ours in spite of our system's bitterly divided nature.