The straw man fallacy, why commit it? Why do people attack a straw man? Put simply, because it's easier. Why defend yourself against the original argument, when you can create a weaker version that has the appearance of the original argument, but not the guts of the argument? That is the beauty and the allure of the straw man. He sits there full of straw just waiting to make you look better! All the while though, the straw man actually makes you look weaker, unintelligent, and dishonest.
I propose three reasons why folks like to attack the straw man instead of the real man.
Let's be honest on this one. Which is easier: to actually study your opponent's argument or to listen to your side's version of your opponent's argument? To go with the former! It takes far less time to listen to William Lane Craig's summarize materialism than it does to read books on materialism. However, which is actually better for you in the long run? Well, if you're going to dialog with a materialist, I suggest you actually read works on materialism so you don't attack a straw man in your conversation with the materialist. Laziness hurts your conversations with your opponent.
If I'm going to converse with a liberal about government, I'm not going to read conservative material alone, I'm going to read as much as possible on both sides before I engage in that conversation with the liberal. I'm not an expert in that manner, but I do have enough knowledge from studying both sides (surface material) to know that I agree with the conservative platform. Studying the other position for yourself will help you tremendously. Don't be lazy. Read your opponent's work. Doing so will not only help you avoid attacking straw men, but you'll also learn why you disagree with your opponent. That is very important. Why do you believe what you say you believe?
Attacking a straw man is easier than attacking the real man. When you attack a straw man you create the illusion that you've refuted the proposition without ever actually refuting the proposition. Refuting the true proposition takes work. We don't want to do that, so we refute a condensed version of the true proposition so the audience listening thinks you know what you're talking about. I'll give an example.
Bill: "I don't understand why 'so-called' Christians believe in three gods; that's heresy!"
Jane: "Are you talking about folks that believe God is a trinity?"
Bill: "Yeah, trinitarians believe in three gods: the father, the son, and the holy spirit."
As we know, the trinity is not a model for three gods, rather it's a model for the tri-unity of one God. The trinity is a monotheistic model, however, popular opinion is that the trinity is a model for three gods. Attacking the trinity by saying it's a belief in three gods is attacking a straw man because you're not attacking the trinity at all.
Did you also notice that Bill appears to know what he is talking about. He used the word trinitarian and father, son, holy spirit; most people know these terms and would have thought that Bill knew what he was talking about when he actually did not know what he was talking about. People like Bill, use rhetoric and attack straw men in an attempt to dismantle their opponents view easily, but one only has to light a match on the straw man to destroy it. Taking the easy way out, at least in debate, will not gain much ground for you. The only time attacking a straw man works is when you're not in a public debate and you're speaking to a crowd.
This reason is not aimed at the philosopher or politician, rather it's aimed at the man on the street that uses arguments he has heard on TV or read in a magazine or book. This man simply repeats what he has read or heard and doesn't know the other side's view. This reason might sound like reason 1, but it is different in that this man is trusting. Reason 1 was aimed at a person that knows better, that would rather attack a straw man because he is lazy than to read his opponents arguments for himself. Reason 3 refers to the folks that have a devoted trust to a news network or man and that has a very trusting personality; I guess you could say the weak. I hate to use that word, but it's best fitting for this reason.
Some people are very trusting, i.e., gullible and susceptible to half-truths. If the half-truths come from a respectable, seemingly intelligent person then most usually the gullible will follow him/her and believe the words coming from the "intelligent" and "honest" person. So, the gullible person doesn't see any reason to check the facts on both sides and inadvertently attacks a straw man during conversations with other folks on the street. I would say this reason affects the most people.
Those are my reasons for why people commit the straw man fallacy and I would be interested to hear more reasons (if any). I can't think of another reason at the moment for why a person commits the straw man fallacy other than what I mentioned above. The uninformed can sometimes be a combination of the three reasons. I don't think every uninformed person is a gullible person blindly following the rhetoric of say, TBN or MSNBC, sometimes a person is uniformed because of reason #1, laziness.
I hope this has been beneficial and if you can think of another reason why a person commits the straw man fallacy comment below.