I understand your view but it is more nuanced. Extensive testing is COSTLY. You need a hazmat suit for each staff involved in the testing process and a tight control of waiting patients. Driving is not as widespread in Japan big cities so forget about drive-thru. The process takes time and monopolizes human power. In 90% of tested cases, outcome is negative, which says nothing about whether a person will get infected the next day. So how to proceed? Test every person every day? Inconceivable.

It is not that simple. Do I wish Japanese gov did more tests? Yes, definitely. Their current requirements for testing could be eased a bit in order to avoid missing atypical cases. Can they achieve the target of getting a clear picture of the epidemic? No it is too late for that.