I've asked a question in freenode channels then idled for the better part of a day, or even a few days, with little traffic and no answers. SO is faster, often much faster.
It really just depends on what you're asking about. My opinion is that IRC is a better medium for common languages with popular open-source implementations like PHP, Python, or C and SO is usually a better medium for languages with popular closed-source implementations, like C# (though freenode's ##c# is sometimes helpful) or ActionScript/Flash. More enterprise people are on SO than IRC, I guess.
It could have just been the case that more experts for the particular area you're interested in were on SO at the time you asked that question. Had you asked a different question on a different topic, perhaps there would have been more experts ready to answer it on IRC than on SO.
Having spent a long time on IRC, I can attest to seeing many people's questions getting answered there constantly, and usually (on the active channels, at least) very quickly (ie. often within seconds or a minute or two). Fifteen minutes is usually considered a long time to wait in an active channel for an answer to a question that isn't really obscure.
Of course the likelihood of an answer decreases with the obscurity of the question, the lack of popularity/appropriateness of whatever it is you're asking about, and depends on when and how you ask the question. The same goes for any other medium of communication.
I'm happy that you've had a positive experience on SO, and sorry that you haven't had much luck with IRC. But that doesn't mean that your experience is a typical one.
I'll take it as encouraging that I've reached the level of expertise where my questions are more quickly answered on SO--I will grant that "where do I find an Ubuntu driver for my video card" will almost certainly be answered more quickly on #ubuntu than on Serverfault or Superuser.
That's not an attitude. That's an appropriate response to assertions you made about the obscurity of questions and unpopularity of platforms that will receive no response on IRC. I realize it was not a humble response, but it was not an attitude.
As to inexperience, I'll admit I've only been on Efnet's #help since 1997-ish and Freenode since around 2005, but that's still much longer than I've been on SO.
My questions are not of the sort "Why hasn't my patch been committed?" I consider this a difference in type of expertise more than a difference in level of expertise.
