No but you should not trundle out the "I'm offended" patter to silence debate. It happens all too often. You can be talking about how 4x4s are now used frequently for the school run and how dangerous they can be for other children and then someone will come along and say "I'm a 4x4 driver and I'm offended by your argument"
Or you can post a light-hearted thread about someone falling over a patch of ice and sliding on their bum and someone will get all stroppy and offended.
Some people will take the chance to be offended at EVERYTHING just because they can. There is no rhyme or reason to it. Surely you've seen the increase on Mumsnet alone? I can start a thread about duck fucking and someone, guaranteed, will come on to tell me that they are offended.
Being offended in itself is not a good enough reason to stifle a debate or a conversation. You have to explain yourself and be prepared to enter into the conversation. Saying that you quite like ducks isn't a good enough reason to be offended by my duck fucking thread.