People call for stupid things on the internet everyday, condemnation simply brings the light of attention to them. You can find far right sites based in the US and the UK calling for a war against Islam, or for everyone with the wrong skin colour to be driven into the sea, or for the deaths of every Catholic or protestant. Spending pointless energy on these nutjobs is futile, acting outraged that bodies haven't raised a protest against a particular example of frothing idiocy is an exercise in outrage for outrage's sake and nothing more.
Iran is not a significant threat to Israel, or the lives of Israelis. Iran, however, does face significant threats to both its existence and the lives of it people.