I wouldn't doubt that some people that cheat and have and have a sex addiction problem may just not be suited for monogamous life, however some people are seriously just addicted to sex and also use risky sex habits such as not using protection and could care less who the sex is with. I have a very high sex drive but I think the difference is I would have to love the person I am having sex with.
I know not all polys relate the two, but I think that is what keeps us from being open and/or swingers and makes us poly.
I could be wrong.
Since knowledge is infinite, it has infinitely fell on me.