I always thought it was clear: it was the combination of Merkle chains with a proof of investment (work, stake, etc), since that combination was the real novelt

I always thought it was clear: it was the combination of Merkle chains with a proof of investment (work, stake, etc), since that combination was the real novelty, worthy of a new name. It was quite confusing to see people calling "blockchain" to one of the pre-existing concepts. It's like calling any wheel a "bicycle".