That’s actually a common misconception.
It’s not because Japanese ninjas are bad at being ninjas, it’s just that other countries ninjas are completely invisible to the naked eye.
Obviously we all know we can see our own country’s ninjas, but other countries are invisible.
Thanks to years of cultural import/export, most humans can naturally see Japanese ninjas.
So congrats, if you can see a Japanese ninja, you’re actually just close to being a weeb.
Yeah, but so are 40%, by their own admission.