No offense to dog owners, but dogs tend to make me nervous. A leashed dog is also unlikely to jump up and leave muddy paw prints on my pants, or to step on my feet, or to lick my face. If you have a dog and a cat, you will rarely have to clean the cat's litter box, because the dog will do it for you. I think part of the reason dogs get so excited in the first place when they go out for walks is because they're cooped up in tiny little houses all day. This is part of the reason I chose to have a cat.
Cats are quiet, restrained and have adapted to living indoors.
Darwin would be proud. If you need to have a dog badly enough that you need to have it in your one-bedroom Pittsburgh apartment, then you can damn well keep it from spreading its joy at being outside all over the unsuspecting populace. Now, I'm prepared to give dog owners the benefit of the doubt. Maybe they think my lawn is dying and needs some fertilization. Maybe the owner is so proud of the dog's excrement that he wants to show it off to everybody.