Let me give you an example. Let us say that an actor was having a seizure in the middle of a play. You, being a doctor, ask the person next to you whether or not you should go and help. In turn, that person sarcastically says that there is no need to go and help as this is just part of the play. Unless you caught on to the sarcastic comments made by your neighbor, it is likely that the actor who was having a seizure could be seriously injured. This is why sarcasm should not be tolerated in society today - a small misunderstanding can be devastating.
Another reason sarcasm should not be tolerated is because of its effects on someone else's self-esteem. Let me give you another example. Let us say you are talking to your friend about the most recent chemistry test. Your friend thought he did poorly, and you did too. Instead of saying that you thought you did poorly, however, you sarcastically say that you thought the test was the easiest one yet! If your friend doesn't catch on to the sarcasm, this will really put a dent in your friend's self-esteem. Having a poor image of oneself is never a good thing.
Finally, sarcasm should not be used because it can give people invalid information. For example, if you ask a friend who killed JFK and the friend responds sarcastically that it was a conspiracy theory led by Lyndon B. Johnson, then you might not catch on to the sarcasm and believe that for the rest of your life. This incorrect piece of information will eventually spread to your children and close family, and will create a misconception that will make you look stupid until you are corrected. This ties back in to the self-esteem aspect.
Oh, man. Don't you just love writing satires? ;)