I forgot to comment on the people who say they're polyamorous, when they mean they're open, or want casual relationships. I too find it annoying, especially since there are so many words for that already and they really don't need to use this one, which clearly has "love" in it.
I only encountered that attitude recently though, relatively speaking. My first experiences with poly folks were long-term established families. Most of my experience has been, really.
I also totally understand not wanting to call yourself something because of how you keep hearing it used. If most people who call themselves something are people you don't want to associate yourself with, you might not want to call yourself that. I understand it for things like a political position or a philosophical one, but since I see poly as an orientation, well that's what I am, and people giving it a bad name can't change that. I can only trust that people I choose to open up to will know me enough not to imagine things that don't sound like me at all, or that at least they will give me a chance to prove them wrong if they assume them.
Just like others, I tend to want strong emotional connections before I'll consider a relationship and sex. I did have an experience with a friend with benefits, but even that was after years of knowing and trusting each other. And really I should just call him a friend, we had a sexual experience once, it doesn't redefine our friendship or change it much, and neither of us is interested in doing it again (nor does either of us regret it).
The idea that poly = easy IS annoying, but I find people think similarly of many things that apply to women and sexuality. As soon as you start talking about your preferences, if you are a woman, it seems it means you're insatiable and will have sex with anyone. Kinky? Then people will assume you're not monogamous. Poly? People will assume you're into casual sex. Etc, etc.