When I started riding snowboards in 1986 at Ski Cooper in Colorado, we had only a couple of board companies to choose from, and the product really did suck. Now, there's a binder, boot, or board for every niche. While some of those products aren't well-suited for the niche that I occupy, I absolutely don't get the hatred towards certain brands.
Personally, I enjoy the opportunity to interact with the people who work at and own the companies that I might have the opportunity to buy equipment from. By seeking out respectful interactions with people like nose in both online forums and in person, I (and other people I know) have had the opportunity to try boards and bindings that we otherwise wouldn't have. We've had our feedback taken seriously, and seen related changes to products from companies like Venture, RIDE, Capita, and Union. Then again, I like snowboarding and the opportunity for exploration that it affords me, and I think that flame wars on teh interwebs are silly... Not that I haven't engaged in them on occasion.
If you don't like Union bindings, why not take advantage of the opportunity to give them feedback by telling nose what hasn't worked for you? He's a dude just like anybody else. If you get confrontational with him, he'll be a dick back. If you give him honest feedback and ask questions, you're likely to recognize tweaks to the product line in future seasons, and you may see yourself getting the opportunity to participate in silly contests for free gear.
Of you could completely write off an equipment manufacturer that was started by snowboarders, is exclusively run by snowboarders, NEVER screws over the "little guy", is the equipment sponsor of choice for some of the more dynamic riders in snowboarding, and whose sales manager spends his time personally soliciting feedback and engaging in conversations with the rank and file riders who geek out on this site and others.
Like everything else snowboard-related, it's all about personal choice.