See... I hate questions like this, because yes, I believe it exists. I've even seen it, so I KNOW it exists. What they're really asking, though is, do you believe that monogamy is the best choice? And that really, in my book, depends on you and who you're dating. For me? Monogamy CAN work... But a relationship is much more likely to persist if me and my partner are polyamorous. That's just me, though, and I know several people for whom monogamy is the ONLY way to go, and it works for them, and that's all happy and good, and I'm glad they've found what works and pursued it.
For me, I have REAL issues with feeling stuck, and it's very hard not to feel stuck (for me) in a monogamous relationship. So for me? Polyamory is absolutely the way to go. Some of this is for the comfort of my neuroses, yes. I definitely have issues about thinking that I'm a burden, so if I can spread the 'load' between people, it makes me feel far less worried that I'll be too demanding of one person. But that's just a small portion. The majority of the reason that polyamory works for me is that I like change. I like variety. I like not feeling like my emotions need to be controlled, and I like being able to openly gawk at attractive men.
I feel the need to make the distinction between sleeping around and polyamory (For me... it's different for everyone, so keep that in mind). For me, I really need to feel comfortable with the guy before I will even consider sexual intimacy. Now, granted, sometimes, it's fairly quickly that I feel comfortable. It all has to do with energy and my gut instincts. I also need to know the 'rules' of the context...
Example the first: I was at a gathering discussing sexual things with sexual people and met a gentleman who I knew through reputation to be...well... a gentleman. We hung out and talked a bit, and later, he and I had some light sexual intimacy (publicly... it was a very safe setting.)
Example the second: I'd been on a couple dates with a gentleman, and knew I was comfortable with him, and was willing to get intimate, but we were in a situation (at his shared apartment with his partner while she was gone) that I had NO CLUE what the rules were, so I essentially pulled a 'friend' move, and we ended up just cuddling. (a situation I intend to remedy sometime soon)
*shrug* So it's all contextual.
Another reason being poly is the best choice for me is that I TRULY believe that I can't be everything to someone. Not forever, at least. Not only do I think it's not possible, but I don't WANT to... I LOVE it when my primary goes off on a date and comes back glowing. It makes me happy that he's able to experience fun things, and it takes pressure off of me if I'm having a bad month or something... I'm not vocal about it really, but I've been fighting depression for a while, and seeing him able to get away from me and that for a bit is nice. It soothes my guilt. (As a side, I'm on drugs now, and the mild depression seems to be lifting... I'm much happier in general lately) Not to mention, that other people have other ideas, and sometimes he'll come back with something he just wants to try with me... and that's perfectly happy. :)
This got long and rambly. Whee!