Can you name which backgrounds you/Japanese people are talking about?
What confuses me is that Japan is not a very immigrant-heavy country. There's no chance of someone who doesn't represent the interests of native Japanese people being elected any time soon, or ever. So why can't they pass laws codifying the behaviors they want to encourage and ones they will treat as non-assimilation? Why aren't they doing something to address misbehavior directly, making newcomers to the country prove their long-term commitment to their new social and cultural environment, or punishing infractions more harshly so bad actors can't stay in the country? Why are the only two options available to them 'do nothing' or 'blanket punish all foreigners because all foreigners are trouble'?
It is part of Japan being Japan. Japanese being Japanese.
Japan is a shame based culture. A lot of social norms are encoded as part of being Japanese and not strictly enforced. Japan has less lawyers per capita compared to US for example.
Take a look at a lot of the influencers that are causing trouble in Japan. In the US we probably bludgeon (or shoot) those people on the spot and lawyers talk later, but Japan doesn’t do that, not even their police. Majority of Japanese just sit there silently but deep inside filled with disgust.
Besides, once these laws are implemented, soon it will be obvious which groups are “targeted” and it doesn’t look good in the eyes of the international world.