If you seek negativity on the internet, you'll find a bottomless pit of it. Homophobia, racism, misogyny, and a million other forms of ignorance, people throw their darkest thoughts out there either because they get to be anonymous, or because they finally have a soap box, or both.
If we're going to dissect the major prejudices people have against poly and figure out ways to educate, well, that's one thing, though I might find the task too depressing even then. But random cruel rantings on other message boards, there won't be any end to it or any sense to it, so why engage with it?
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.