After I saw it, I was really confused about the gambling site. And if I do it maybe I will do it with feeling without knowledge and that's certainly not a good idea when betting.
Betting on politics is same as betting without knowledge. 
Its more like a, "I support this nominee, so they will win" situation and definitely not something that you do for money but for fun and time pass. I mean votes are basically a showoff, its already decided who is going to win even though common people would not know it. In some countries voting is so much rigged than most people dont even go for voting.
So its like a fixed sports match and you dont even have any idea whom to bet on. Its better to avoid it, in my opinion.
I agree with you that we should avoid betting like this, but in my opinion not all countries cheat when voting. There are still many countries that are fairly fair in voting, in my country the voting is done in realtime with witnesses from both parties and if there is cheat, surely only certain individuals are carried out in some areas. But so far I don't recommend politics to be used as a gambling match.