I have been on Stack Overflow for well over a year now, and I can say first hand that some users are very rude about answers. Some could actually call it condemning at a certain point. I understand most users don't know that I am a college student still learning how to program. Is Stack Overflow doing anything to make sure that people aren't being scared off the site with rude comments and being talked down to because they don't understand concepts that may be simple to others?
Rudeness is never acceptable on StackOverflow. That said...
I assume you are referring to this question: Is there a certain reason that true and TRUE aren't the same as True in python?
We have had so many bad questions asked on StackOverflow in the past year that StackExchange has instituted some automatic quality filters to intentionally block the worst of the worst questions from being asked at all.
The remaining questions have to pass through several conceptual filters, one of which is: have you done your homework? Does your question demonstrate that you have performed a minimal amount of research already?
I am personally a big believer in being polite. But if you've seen the sewage I've seen pass through here, you would understand why we get a bit crotchety sometimes.
I would say that if you are asking questions that can be easily found by doing a couple minutes of Googling you are going to get people that will be rude to you. If you take the time to write a good question showing what you have done to try and solve your own problem before just asking for help you will get a much better response from people. Therefore, if you are trying to get a positive response out of people with a well thought out, friendly answer you need to put the time in yourself by doing some research and writing a good question.
Most people I have seen answer on SO are not rude but I tend not to look at questions that people don't try to answer themselves or that are so poorly written I cannot understand them.
For the question cited:
There was a bit of frustration expressed over such a simple, basic question, but I don't think it would be fair to characterize it as overt rudeness.
That said, per http://stackoverflow.com/faq#etiquette