Does Alpine Linux install non-free blobs without letting the user kow?

"And to my amazement found that OpenBSD does the same: https://marc.info/?l=openbsd-misc&m=143354954711286&w=2"

It really would have been good if you had read more than just the first message in that thread. The next message is a rebuttal from Theo de Raadt of the accusations in the message you cite. Other developers chime in later. The original post was nonsense.

Then I suggest that you think hard about what Theo had to say. *You* made the decision to buy a particular bit of hardware. I think it's fair to assume that that means that you want to use it. The hardware we are discussing needs firmware in order to operate. If that firmware is in ROM in the device or in writeable memory in the device, *it needs to be there, or the device won't function*. So in the cases where the memory is writeable, you are really asking that the OS ask you "do you want device A to function or not?". That's a question that doesn't need asking, in my opinion, and won't be asked if the firmware is in ROM (so it's odd to be complaining if the question doesn't get asked when loading the firmware into writeable memory; what difference does it make what kind of memory it's in?). If you were/are concerned about the device's firmware containing backdoors, then either you should have thought about that before buying it, or you should remove the device, if possible, from your system, and replace it with something that makes you happy. Theo is right -- this is an issue created by the end-user by her/his choice of hardware.