There is something brave about creation tools being made by a developer and then handed over to a community. In a lot of cases, more or less by sheer man power, the audience might well be creating better designed levels than the actual creators with the tools.
Rather than be intimidated by that, Nintendo producer Takashi Tezuka has said that seeing the community's ideas has been inspirational and is bringing the developers to work harder. Speaking to Edge (via GamesRadar+), he said:
I've been watching lots of different courses on YouTube. It was quite a surprise how much fun it was to watch the videos, without even playing myself. There are so many intriguing and inventive courses, like one which you couldn't beat if you picked up a mushroom. It's been a huge motivation for us developers to do better.
It's good to see the developer taking notes from the community. I have seen some ludicrous levels being made, full to the brim of ideas. Nintendo not taking notes would be wasteful.