Makes sense if you are out running or cycling or doing some intense cardio workout but otherwise its stupid not to wear a mask. Even if you are working out the risk of spreading the infection if you are an asymptomatic carrier remains. Tricky situation. But few people just don't want to wear one even if they aren't engaging in aforementioned activities. Seen this in my city too, even in supermarkets early into lockdown! Now they don't allow people without masks in most places.