As someone who is allergic to them, i'm so glad that they are discouraged from being on a packed train with me. If i get dog dander on any of my clothes they need to be washed with hot water immediately or everything else will be contaminated.

Being stuck in a small space with a dog (lots of hair and dander in the air) causes my eyes to turn red, welts to form on my skin, and have trouble breathing. Even if I never touch the dog, we're using the same space.

Also I know multiple neighbors on my block who refuse to pick up after their dogs. They still let their animals go to the bathroom wherever they want but at least they steer clear of my treepit after I confronted them and told them I was going to follow them home and load their mailbox with their own dog's shit from my treepit. It's really a shame that it had to go that far....