They are not just asking for more money, from TFA they are imposting additional requirements like better Japanese fluency etc. In general they are raising the bar for who is allowed to live there, and all of that protects Japan.
No, that's not required for this visa. The capital requirement is the major change. Also, foreign restaurant owners are already fluent in Japanese, because they deal with Japanese customers every day. The language requirement change is for other visa types.
The rich people abusing this visa as second home have no trouble depositing a bit more money to meet the requirement. It only affects legitimate businesses that can't raise and float that kind of cash. It's performative punishment to appease the growing far-right sentiment. If they wanted to verify businesses were real, they can go there and foot and inspect. (They already have the right to do this, and all businesses that qualify for this visa must have a public office or commercial space with a clearly listed sign that can be accessed easily.)
Also, they enacted the change and applied it retroactively to existing visa holders who were waiting to have their visa updated. So people are now being rejected on new rules that were announced and enacted after they had filed to update their visa (which you must do every 1-3 years.)
Japan is not a theme park for foreign tourists to gawk at. It's a real place where people live and work.
It was more obvious before you edited the comment (and in principle we appreciate it when people edit their comments to dampen or remove personal attacks), but the bit that begins "Do you live there?" and ends "boot such gaijin out" is still saying much the same thing. You can make your substantive points without getting personal like that.