I don't think anyone has spewed hatred for dogs. Most of the posters have dogs.
I think most folks have taken exception to ppine's comments to take your dog and do what you want because the rules are stupid.
Most are recommending that the OP look at the rules and: 1) find a way to bring the dog while following the rules; or 2) don't bring the dog.
Disregarding the rules so you can bring the dog on your terms is what gives dog owners a bad name and gets dogs banned from places.
Yes, people have and do bring their dogs to Yellowstone. But knowing the rules in advance and figuring out how to keep your dog safe and happy, to see the sights you want to see, and to stay within the rules, will make your visit a much more successful one. And sometimes, to make all 3 of those happen, it may be "leave your dog home for this trip".