Not OP but I think it's because it's just difficult to spot it. It's also possible that the clarity of this kind of ice shows the often-black (asphalt) road surface through it without any obvious sign that there's ice there. Could also be a connection to black/evil/cursed.

Probably a bit of all three, depending on who you ask and how they think about it.

The opposite/corollary of black ice is white ice.

Prior to asphalt - paved roads the term was used for clear ice over deep water.

Black ice is stronger than white ice, which is important if you're deciding whether it's safe to drive over or put an ice-fishing shelter.

It's also a hazard for rock climbing and scrambling, because it's just as unexpected on a rock face as on a road or bridge (well, maybe more expected on a bridge because they're known for it).

We could call it ninja ice

In America, they call everything they don't like black.
I think it has historical reasons.

Because it's effectively invisible, and roads are black.