I believe I read where people where out in a park (maybe Central Park?) and the governor told them they had to stop going out and being in groups. That they would start arresting if they had to but that he didn't want to.
I think they are really just trying to get people to be sensible. Even outside, if you are in a relatively crowded area you run a risk. If you are constantly passing by people on a bike path or in a crowded park, there's some potential risk.
Because some people take "you're allowed to go outside", as giving an inch and they take a mile. And then you have people getting together outside which is defeating the point of social distancing.