My first guess would be because these passes can be used in Apple Wallet.
In response to your edit (ignoring that you used a piece of hardware for that example): Apple makes a lot more software than ASUS. Everyone knows the software is part of an Apple product; that's been a thing the whole time macOS has only been (officially/easily) runnable on Apple products.
amelius · · focus · HN ↗
What is next, ASUS making electric bike motors?
jacobgkau · · focus · HN ↗
In response to your edit (ignoring that you used a piece of hardware for that example): Apple makes a lot more software than ASUS. Everyone knows the software is part of an Apple product; that's been a thing the whole time macOS has only been (officially/easily) runnable on Apple products.