Earlier quoted context omitted.
I doubt his kids would be killed in Austria/Switzerland/New Zeeland. Plus, the former head of Mi6 warned not to try and corner Putin, since if he were to be personally severely threatened, he wouldn't hesitate to turn to using nuclear weapons and take the whole world down with him if he were to ever be ousted form power by the west.
"Not cornering Putin" just means giving him what he wants. It is the opposite of what we need to do - show how weak he is and let his own people give him Gaddafi ending.
Never gonna happen because:
1) The majority of the Russian population is still supportive of him, thinking they're fighting to liberate Ukraine from nazis and that the western sanctions are in place because the west hates them, rather than consequences for their leaders' war crimes
2) Like the former head of Mi6 said, Putin is so mad that if threatened, he's more likely to be ok with seeing the whole world get nuked, instead of going down like Gaddafi did, which is why the west is going so soft on him.