Most debates aren't backed by physical facts. Hence why they are debates.
Pro-choice vs. Pro-life is a typical debate. The better debater is the one who can put together the most compelling case that their perspective is the right one.
It isn't the conclusion that a good debater battles against, it's the assumptions made by the other guy.
Hence, when someone says "Program X" is "buggy". How can you "prove" that it is not? There are lots of variables involved and hence a good debater will try to 1) find out what definitions they are using (what makes something "buggy") and in what context are they saying it is "buggy".
One debate Doreen and I have touched on is a timeless one: "What is success?"
Is success simply the process of achieving a remarkable level of happiness? Can people define success on a person by person basis?
That is why qualifications are needed. For instance, when I said in that custo debate that it is the "slum" of the community, the term "slum" was an calculated word - a qualifier. What is a slum? For most people it is the area of town that not many people live in, few people visit and those that live there are "low class" (another debateable term) and "Crude" (another debateable term too).
On the Stardock forums, there is a debate as to what is the nature of evil. What makes person A "Evil" but person B not evil?
It's those kinds of topics that make the Internet interesting and lively.
BUT..
In some places debating isn't appropriate. If people feel like every single casual statement they make is going to get jumped on, then the forum they're on can feel hostile or unwelcoming and people will leave. That's why I've tried not to be involved in too many debates here. People don't come here to debate so I try not to get involved in them unless it's something I"m passionate about.