Nintendo isn't your school teacher for pete's sake. They banned all people who went online because it made financial sense to do so. Big release! New Pokemon - millions of copies to be sold. Suddenly, people are online. Who can be online this early? Only people with cfw and access to the leak. Kill the Internet functionality. Do it in waves (possibly to filter out there own people OR many people made the mistake of going online). The company made sure that some users are going to buy new hardware to replace their own defective ones anyhow.
(Also, I'm pretty sure Nintendo did that on purpose. Leaked a copy of Pokemon Moon early so that they could catch all the people using cfw.)