Sure; I'm aware that embedded sucks. And to be clear, this is (IMHO) tolerable so long as the blobs are redistributable. But then maybe don't headline with "100% open source". It's better to be honest about it.
I see that kind of thing more often labeled "open hardware" rather than open source.
Yeah, it's weird because they're the ones writing that headline, and the claim is that it's 100% open source. They didn't have to word it that way, they chose to.
I see your point, but it feels more like the difference between 99% fat free and 100% fat free. Technically measurable, but irrelevant in practice when the alternatives are all basically closed source.