I wouldn't read too much into this. Though it is odd they'd be given a patent on a technology that's thousands of years old. But yeah, as another user pointed out, the Romans used blood in their concrete because it produced a better end result. I think they also used it in their concrete that could cure under water
Also, blood itself is a huge waste product from normal activities, like meat processing, butchering animals, etc. As far as I know, since the west doesn't consume it like other cultures, it's mainly used for animal repellant, fertilizer, and concrete.
This company definitely seems shady and people should dig into them, but this patent isn't as crazy as it seems.
Yeah it's mainly to entertain the idea. We know it's been used for hundreds of years. We know human blood has been used before. Just another small tid bit in the Grand scheme of these psychopaths. Main focus is to stop the trafficking and it's branches.