The main hiccup is the system is off by a day. Some people "fix" this by saying the extra day should be "new years day" or something similar that exists outside the main calendar and doesn't have an actual date or day assigned to it. Personally I think that's kind of silly but it does work.
The second problem which to me is a much bigger problem, is he argues every month starting on Monday is a feature, I think it's a bug. The result of this is every date is the same day, every year. If you are born on a Wednesday, your birthday will always be on a Wednesday. I like it mixing up and getting to have your birthday on different days.
Also almost everyone will have a new birthday they have to learn and too many people would simply be unwilling to go along with that.
And all that is ignoring the monumental task of changing every computer system in the world.
Edit: also 13 is just kind of a rubbish number to work with and doesn't divide into anything nicely.
I'm fully ready to get torn apart for this. I get victim blaming is wrong. But sometimes you can make better choices based on available information, regardless of whether it's your fault if something happens.
If there's a street called Drag Race Avenue where every person that lives on it drag races up and down it all day and every week there's a news story of someone getting hit using the crossing on Drag Race Avenue, maybe you shouldn't use the crossing on that street. Sure, it won't be your fault if you get hit, but how much comfort will that be when you're injured or dead?
It's possible to make choices that are objectively morally/legally/ethically right that are still stupid choices. Unfortunately we don't live in a world where as long as you do the right thing, so will everyone else and nothing bad will ever happen to you.
Hazards are a part of life. In many if not all workplaces there are hazards. Due to this there are hazard controls, along with a widely accepted list of most effective to least effective ways to deal with a hazard. First is to get rid of it entirely (stop people drag racing on that street) but if that's not possible, the next 2 are replace the hazard then isolate the hazard. In other words, if something exists that you can't stop from existing, your best course of action is to stay away from it / out of its way if possible.
These controls aren't about victim blaming, they're about making hazards as safe as possible. It's not illegal to carry a box that's too heavy for you, but you still may be injured by doing so. There's a reason workplaces have 100s of policies that aren't illegal but they decided you can't do there. Because there are many things that exist that you can do that are entirely legal but could still harm you.
Emulators might not be illegal, but Nintendo is a hazard to them that can't be eliminated.
I guess it depends on whether you care more about being right, or more about being safe.
These people could make the choice to be safer if they wanted to. They could be more anonymous if they wanted to. They could stay out of Nintendo's way. But if being right that they're not doing anything wrong is more important so be it. Maybe they consider it worth being shut down in order to draw attention to the issue. That's up to them.