Countries, as a rule, don't have a right to exist. People have a right to self-determination. These are different things. That said, Israel is fundamentally an Apartheid state. If Israel stopped being an Apartheid state it'd stop being Israel. And if a state needs to treat half the people in it as second class citizens to exist then it can go die in a ditch.
This isn't just an article about a little girl being sexually assaulted; it's an article about a little girl being sexually assaulted and the effect of that on French politics. People saying "but there's a genocide in Gaza" are concerned about the latter half here.
It's not far fetched to see antisemitism being an issue and think "they're gonna come after the anti-zionists too". This comes up in the article. This isn't "all lives matter".