If the old one could still be used, they shouldn’t send a new one anyway.

Well, if it can still be repaired but the producer doesn't want to bother and just sends a new fan, that's fine. That doesn't mean a repairable product should be destroyed and sent to a landfill just because it makes Noctua's logistics easier.

The point is, if the owner thinks it can be repaired, they shouldn’t call for a replacement in the first place. And indeed they wouldn’t get one, because they wouldn’t break the blade. So it’s completely under control of the owner.

Sure but the owner could've technically been left with a spare part in this case

Though it's not that likely that users will try to replace the blades on a fan.

But would it be more wasteful than shipping a parcel with broken equipment?

It’s a chilling effect on folks that buy one noctua fan and want to get another free one by claiming the first one is broken.

Anecdotally, when my Xtrfy MZ1 mouse cable started shorting 5V to ground, they required a similar process (cutting the cable) before sending a replacement.

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.