No.
For one thing, life is too short and my own life is full enough of things to be concerned about to bother worrying about what someone wears while walking their dog.
Secondly, you simply never know what is going on in peoples' lives. Disability, exhaustion, illness, washing machine's broken, lost all their clothes in a fire, bloody hell could be anything. Judging people for superficial things is always a path to misery.