There are so many fallacies in this post. A lot of the gay community is fiercefully faithful. You are making excuses for your own behavior because you feel your own desires and personality need to be excused. THAT is a product of our social construct. There is nothing wrong with the way you are choosing to live your life. But for many people companionship is desirable and a basic human instinct if you ask me. It's why people tend to go back to the familiar. We enjoy the comfort and satisfaction of not needing to impress. There is certainly allure in the new, but I feel that allure comes from the necessity to feel desirable to the opposite sex and less to do with "we aren't wired to be monogamous". If your partner makes you feel uninteresting you'll seek affection elsewhere. Humans are diverse creatures. We all have different wants and needs.
Monogamy isn't a problem, the social stigma attached to people who decide not to adhere to that norm is.
What part of *generally*, prefixed and suffixed with stars specifically to curtail cherry-picked responses like this do you not understand? I put that there specifically to avoid a "but my Gaybors in the condo next door have been fiercefully faithful for years-- FALLACY IN YOUR FACE". Obviously there are loyal monogamous gays, duh, but if you think on the whole hetero and homo relationship dynamic is the same, you are either deluding yourself or are trying to be hopelessly PC. Step into your average hetero nightclub at one AM in LA, then go visit a gay nightclub in West Hollywood, then let me know if you notice any differences besides the gender mix.
As for "making excuses", I make none. Ultimately everyone is responsible for their behavior and actions-- it's one of the qualities that separates us from base animals. However I would argue that the base urges/desires I mention are present in all men to some degree-- some are better at dealing, repressing, ignoring, overcoming, etc than others. That whole "diverse creatures" thing you mention.
"Companionship", "love", and the desire for the "familiar" are indeed basic human desires, yet you seem to think these are mutually exclusive to "sleeping around" or wanting a variety of sexual partners. How many guys do you know who are married, "love" their wife, "love" their kids, are technically a great father, yet sneak out to the strip club all the time, and cheat at every opportunity? I've encountered way, way, too many myself. This is the guy that works hard, brings home the bacon, attends his kids' soccer games, buys his wife flowers every Friday, etc-- but just isn't turned on by his wife anymore and doesn't feel like destroying his whole family over a divorce. He likes the "familiar, he likes his wife's "companionship", but he needs sex from other outlets. These guys are legion. Now, I am not in any way, shape, or form condoning this behavior, and I am not making "excuses" for it either-- the guy makes an active, conscious decision to stick his dick into someone that isn't his wife, however I DO recognize and understand the impulses and motives behind it. Women associate sex with love. Though *again* there are exceptions, generally a woman that continues to sleep with a man will either a) fall in love or b) leave to find love. Men don't necessarily need to associate the two. When a woman is having an affair, it either ends quickly or continues on until she falls in love and divorces her husband. Women need to feel love and feel desired. A man who is having an affair who cares about his wife (and yes, I realize "care" is ironic when he cheats) generally doesn't want a divorce, he just wants extra-marital sex while maintaining the companionship, stability, and familiarity he has back home. While you always hear "When are you going to leave your wife for me!!", how often do you hear "when are you going to leave your husband for me!". It happens, but not nearly as often..
As for there being some social construct where being unmarried is taboo, I don't know whether you just live in Utah or in the 1950's, but I've never felt it. Marriage is certainly no accomplishment, staying together is. Every married friend I have is jealous that I'm not married, and I don't think anybody has ever batted an eyelash when I've mentioned that I'm not hitched. Would I like that fairy tale marriage/relationship? Sure, but I'm not going to compromise or settle-- there are certainly enough examples both in life and on these boards as to the results of that..