You're not exactly being equal or impartial if you're judging an argument based on the politeness of the people presenting it rather than the evidence used to support it. In fact, you're being about as biased as you can possibly be if you say, "Well gee, they're being rude, therefore their argument holds less weight."
Bear with me, as I'm only about 10 minutes in, but giving both sides my equal impartial judgment, they both sound pathetic. Quite a few of the berating posts in this thread could easily be used against the other side.
Let's say this was not about something so controversial. What if the debate were about whether or not the world is round. Now, if I provide evidence to support the claim that the world is round, but start yelling and insulting anyone who disagrees with me, calling them all a bunch of c-words, does that somehow invalidate my evidence? I mean sure, it makes me a jerk, but me being a jerk has nothing to do with whether the evidence supports my argument.
Likewise, there is a crap-ton of evidence supporting the theory that life on Earth evolved over billions of years. Creationists' arguments aren't based on evidence, they're based on emotion - they just feel in their guts that evolution couldn't have happened, even though the record of our planet's history, even as fragmented as it is, makes it pretty damn clear that it did. So yeah, you're going to have people be disrespectful toward that group, but it doesn't change the fact that said group does not and cannot present evidence to support their outlandish claims beyond, "Well, it just seems like kind of a stretch to us and it goes against what our holy book says."
And don't get me wrong, polite and civilized discourse is always preferred, I'm just saying that the discourse and the evidence are two separate things, and one does not change the other - being forceful and rude is not in itself grounds for throwing your hands up in the air and saying, "I don't know, both sides are about equal to me."