There are lots of reasons people might not want to be spied on, other than being criminals. Not wanting their abuser to find them. Not wanting their neighbors to ask nosy questions. Worrying that someone will hack the feed and use it to hurt them. Missing the land of the free.
One subtle effect is that if there are cameras in all the public places, people who dislike cameras will then dislike public places. That means they're less likely to spend time in parks and more likely to stay at home where, if they have shopped carefully to avoid spying appliances, they are free from surveillance.
This is ruinous to a healthy society.