Yes, absolutely. Sarcasm poisons the well of conversation like nothing else. When people disagree and provide an argument you can have a conversation about subs

Yes, absolutely. Sarcasm poisons the well of conversation like nothing else. When people disagree and provide an argument you can have a conversation about substance. When people disagree and provide no argument or a personal attack, it's easy to dismiss and move on from there. Sarcasm leaves you hanging precisely because it's hard to identify - is the person serious so you should continue to put effort, or is he not serious and you should quit this discussion? As to practical concerns - it's not the goal to catch every single instance of sarcasm, but rather to identify people who like to use it. People of this kind will be doing it regularly, and with various degree of subtlety, as such they will be caught in the act sooner or later.