I think Muslims need to understand something uncomfortable.
Non-Muslims do not owe Muhammad their respect. They do not believe he was a prophet, and some do not even consider him a good man. You can disagree with them, but you cannot demand that they see him the way you do.
Your reverence for someone does not create an obligation for the rest of the world to revere him.
So, are we going to kill everyone who insults Muhammad, or are we going to learn to practise our religion in a world where not everyone shares our beliefs?
Because the world is not going to become Muslim just to protect our feelings.
We have two choices: learn to live with our differences or spend our lives fighting a world we cannot control.
You cannot force people to love your prophet by making them afraid to criticise him. You can only teach them to fear those who claim to love him.