Zoonosis isn't just a risk from pets, wild and farm animals carry infections too and we are also able to pass on certain infections to them. A clean and well cared for pet is less likely to be a problem than any other animal, despite our close proximity to them.
You only have to look in your own circles, most people have a pet of some kind, how many have you ever known who have come down with a pet to human infection?
As for 'poop', lol, yeah dogs in particular do seem to have a bit of an obsession with it, there are a few theories as to why, such as in infancy the mother will wash and clean their young including ingesting their faeces, dogs that have been punished for mistakes while house training may develop a habit of eating it in order to avoid such punishment and in general dogs are just greedy and will attempt to eat most things, lol.
Mine had a fondness for rolling in horse and cow pats, as I live in an area surrounded by fields of cows/sheep/horses this happened a few times, luckily, he developed a loathing for water at about two years old, he had never been a fan from the start, and once he realized every time he did it he was going to get hosed, it cured him. He would look lovingly at it as we walked past, lol, but the word 'hose' was enough to deter him.

If you want to remain free from infectious diseases then you shouldn't keep other humans in your home.
