It seems to me many people on here vote based on their bias, not who did a better job debating their point of view. This being said, I feel like that is unfair. Maybe you don't like someone or maybe you don't agree with someone's point of view, but a debate is based on evidence, credibility, the ability to rebuttal, the ability to prove something beyond a reasonable doubt prosecution (for), and the ability to hold their position of "truth" defense (con).
It's perfectly simple. I agree, I think it's ridiculous that some people start these obvious debates, taking the position where they are guaranteed to win, but it's the people who actually accept the debate who are the real idiots. If losing upsets you, then don't take the position where you are probably going to lose.
Although there are many times where this doesn't qualify, it appears that when you are able to start a debate, you are able to choose the most favorable side. This is why I join debates rather than create them because I want to be challenged. I believe that this website should do a random generator for sides once two people have accepted the debate. That is how it works in actual debate competitions, as I have been involved in many.
There are two issues with suggesting that it is "unfair."
1) People must voluntarily accept the "unpopular" side. If you set a debate up for such an obvious win, no one is going to accept it so it makes no difference.
2) Just because a side is unpopular doesn't mean that it will lose. There have been a number of people that have argued for racism and won, simply because they provided a much better argument than there opponents. I have successfully won debates on topics such as "white separatism is not racist." You cannot simply say "I support this popular opinion" and expect to win.