This could be a good idea for several reasons:
1. osu! can make money? from selling it on the Switch.
2. osu! can get a larger following because the Switch is very popular.
3. You can use the touchscreen feature like Deko said.
It could also not work for several reasons
1. Most people will probably fill up their storage data from downloading beatmaps.
2. Copyright problems like Flanster said.
3. You can't really use touchscreen with your bare hands because if you play very hard beatmaps and you try to do the spam circles, you'll fail.
.