Nobody should give a flying fuck what “Tendy doesn’t like” because they are not entitled to dictate what people are allowed to do with their own property.
The owner of a copy of a Pokemon game has every right to edit his save file, in exactly the same way that the owner of a paper copy of a novel has every right to cross stuff out and write his own fanfic in the margins. These are fundamental property rights that have been well-established for hundreds of years, that Nintendo and other megalomaniacal copyright tyrants are now trying to destroy.
In the long run, shit like this is theft from the Public Domain.