Asymptomatic is where the question really is. If we were in this situation and had a society who knew and was used to wearing them I’d maybe be supportive of a temporary requirement. As it is we have a society who isn’t used to it and uses them incorrectly. If people are going to use them correctly absolutely wear them any time you go out. I don’t think we are there.
Here’s a question for people. How many masks do you have? If you have a washable one how often are you washing it. If you use it right you shouldn’t be using it more than once.
Not necessarily true. The virus dies after a certain amount of time outside the body, varying based on the type of surface it's on. So, if you're taking the mask on and off multiple times per day then you should have multiple masks or wash between uses. If not, simply take it off without touching the parts that were in contact with your face and wait for the virus to die off before using it again. Only wash it if you feel its dirty like you would wash any other piece of clothing.
Now if you have an N95 mask or something with a filter, then that filter becomes clogged over time and has a limit on uses. But that's kind of a different animal.
Something to keep in mind is that it's pretty likely that unless you are a medical professional or other trained person, you aren't going to use masks exactly correctly. People are people, just because in Southeast Asia people are more likely to have worn masks doesn't mean they are all experts in the proper use of the masks. They may know a little more or be a little bit better, but as a whole population there are still going to be plenty of people who are using the masks incorrectly.