The issue here has a lot to do with conditioning and association. It's very much like associating most Chinese to either be really book smart or to know martial arts. Or even associating African Americans to violent crimes. Although statistics may prove your assumptions to be generally accurate, it does not help the fact that your initial behaviour towards those that do not fall into this generalisation will be biased.
Like with the idea of marriage. Statistics shows that it generally fails. So why should you even bother getting into this mess? This is exactly why the reason people get married is vitally important. You don't get married because you're afraid the other person is gonna deviate. You don't get married so that your partner won't move somewhere else. You don't get married because the two of you got pregnant.
Marriage is the assumption that what the two of you have is special and not some normal general feeling that most people get married for.
So, the question is not whether people can be monogamous or not. I believe anyone can. The thing to ask is why should you shut that option completely out of your life? Who knows man, you might find a really nice girl and she could be a really good wife, but your mind is always gonna start putting doubts in your head like 'she's probably gonna change' or 'she's still a girl and they're all the same'. Stop limiting yourself. It's just like saying 'she probably doesn't find a guy like me attractive'.