Everyone knows it's offensive in this case.
Life would be much better if people didn't go out to offend others. Most of us can manage not to.
It depends on what they are being offended by. If people are going to out to offend people on the basis of race, sexual orientation or religious discrimination then yes, I 100% agree with you.
But if they are ridiculing people over something ridiculous then no, life is demonstrably not better for people keeping quiet and allowing the status quo. I've already written a massive post about religious taboos and the danger of not confronting them so I don't want to go over all the same stuff again, but it our world is not a better place for polite society to bury their head in the sand and act like people who create and share satirical cartoons are the bad guys.
This contributes to a society where individuals believe they are justified in beheading someone for drawing, publishing or sharing a cartoon. Well meaning people insisting that to ridicule Islam is to discriminate Islam and helping to create a monster out of something so simple and meaningless.
Publishing, sharing and showing the cartoons removes the power from them. Everyone has the right to be offended by them, even angered by them, but that doesn't mean they should be hidden away, because that only makes them a bigger deal when they do emerge.
These are not images of child porn, gore, violence or any of the other things people have tried to equate them to in this thread. They are harmless cartoons which offend members of a religion who follow a particular interpretation of a religious text. They should be displayed widely and loudly and as much as possible. A lot of people would be horribly offended for a while and then they would get over it and the world would be a safer and more reasonable place than the one we create by hiding them away and hoping nobody ever shares one again.