Nintendo is unique in that they have a rather silly number of classic old games that they still make money off of to this day, so it has never surprised me one bit that they like to keep free fanmade alternatives that are often little more than enhanced versions of their own releases off the market. That's entirely reasonable to me... they need to show people that their intellectual property will indeed be protected and by this point everyone should be well aware that it will be.
They generally go after anything that is similar to a product they themselves plan on releasing, which makes plenty of sense. Just recently, for example, they initially shutdown the Kickstarter for that Nintendo art/coffee book until they'd laid out some guidelines and rules, and just a few weeks later we learn Nintendo is also releasing their own very similar book.
It really appears that whenever they have plans to release anything, be it an old game, new game, or some other product, they look around to make sure someone else isn't basically ripping them off and selling/giving away something similar.







