I don't agree with it being a sign of people getting offended on the behalf of others.

For one, there are a lot of Jews outside of Israel.

Apart from that, I am offended not just because it's disrespectful towards a particular minority. I'm offended because this is a thoughtless comment which "jokingly" parrots hostility towards other people at a time when I'm already worried about how that kind of message is being spread in earnest by a large number of people.