Blobs

As you point out, the issue is not just blob vs. eeprom, other aspects are more interesting: Is the blob freely redistributable or just by "Linux"? Is the blob non-mutable by some draconian US law? What about patents, do the blob carry an implicit license for them?

Even the question of eeprom has shades of gray to it. The device in itself is a black box and its inner workings unknown so non-free code inside it makes little practical difference for the programmer. But if you're supposed to send undocumented binary data as part of the API you blur it and makes programming unnecessary hard. It can be much worse than duming a blob as part of initialization.

I have respect for OpenBSD and the FSF for taking a simple stance on this issue. Not all blobs are equally bad but when you have an operating system with hundreds of drivers their rule of thumb probably helps.