Yes, because these people are alive! Muhammad SAW maybe alive in your heart but he is dead and so is Jesus, Moses, Buddha, Krishna, etc…
People do make fun of Jews, homosexuals, and disabled people all the time, and it IS immoral. Muhammad SAW was an Islamic leader for Muslims not for the world, do not take away their right to speak whatever the hell they want. At least they are not killing anybody because of it. It’s funny how Muslims will wreak havoc upon seeing drawings of Muhammad (why search for them?) and then feel absolutely nothing about a woman who’s been raped and killed. Where do we draw the line? Where’s morality? Where are your priorities?