Everyone has things that annoy them. I don't like being around smokers. My eyes get dry and red, I cough, and I hate the lingering smell. For the most part, there are not smokers around me at any given time. If I see someone smoking, I can easily choose to walk away. The same goes for dogs. If someone chooses to avoid dogs, it's really quite easy to do so. If, by chance, you were in a location that had a dog, you could easily avoid it. If you're in a restaurant that allows pets and don't want to be seated near it, all you have to do is ask.
Regarding the whole dog poop thing: I know there are exceptions, but most people that choose to walk their dogs in public places are really quite diligent about cleaning. I think humans are the gross ones! It bugs me to no end to see people toss their gum, half eaten food, or empty cups on the ground. Heck, I've even parents stash dirty diapers in bushes or just throw them on the street because there wasn't a trash can around. How's that for respecting your fellow humans?