>>34965625It's actually because of Nintendo. They're still in the mentality that a large chunk of their fans don't have access to the internet, and therefore cannot download patches online. So they simply don't do online patches altogether. There are a handful of exceptions like Smash 4, but Smash isn't nearly as popular as Pokemon.
With their online services becoming pay to use, they might start thinking otherwise, but I wouldn't get my hopes up.