You're crazy if you expected the Israelis to just sit back and watch 1200 innocent people get slaughtered. There needed to be a strong response. If not, that kind of behavior would be encouraged in the future.Yes it was barbaric. What is equally barbaric are the Israeli war crimes against the Palestinians. People also do not support Hamas. They support Palestinians, who are civilians.
At least Israel gave the Palestinians time to leave the area before carpet bombing by opening up a humanitarian corridor. If the civilian palestinians didn't leave, unfortunately they're seen as a combatant.
War is not fair.