I've seen a few posts on Fetlife in the last few months that follow a simple pattern:
People (usually guys) who don't want to sleep with overweight women are bad.
One such post even went as far as to claim that the only reason someone would state a body type preference is their lack of penis size.
Let's have a mature discussion around this.
We don't (and shouldn't) shame preferences around gender. People who are exclusively or more attracted to a certain gender are not to be shamed. We accept that, as well we should.
But there are other body preferences as well. Many people have sexual preferences around height. There's nothing you can do about how tall or short you are. And someone may be attracted more attracted to someone who is more muscular, or has larger breasts, or a large penis, or lots of body hair (or all of the above at once). That's who they're attracted to, and it's just fine to have such preferences.
I think the real issue isn't who one decides to sleep with. The real issue is externalizing that preference into a value judgment. It's one thing to say "I have a preference for taller people" and another to say "Short people are bad." (Randy Newman not withstanding).
A sexual preference is a sexual preference. It's okay to have them. It may limit your options, but hey that's okay too. What's better, though, is owning that your preference is your preference, and not a reflection on the person you are, or aren't attracted to.
In summary: Being attracted to a certain type of person doesn't make you a jerk, but blaming the other person for it does. And stating it loudly and obnoxiously will very likely get you rejected by people who have a preference around wanting to sleep with people who aren't jerks.