I get why. But that still seems wasteful
Though it's not that likely that users will try to replace the blades on a fan.
This was their response when I asked why: > Yes this policy was put in place because there was multiple instances of people reselling their faulty products after receiving a replacement.
> The secondhand buyers then reached out to us, let down to have received a broken product.
I'd imagine it's a similar reason for Noctua.