As somebody who works in the space, you've just hit a topic that annoys me to no end. The term "Blockchain" has a very specific meaning, and that is just a specific type of data structure (that also happens to be used in Git, as you describe). The whole meme around anything that's even remotely like a large scale distributed (not even decentralised, as Bitcoin is!) system being called a "blockchain" is literally worse than useless, because it has no precise meaning, and has robbed a word from a perfectly fine, well-defined meaning.