Well, Git's also not a blockchain at least in the way commonly meant by the term. But yeah, it'd be a pretty bad bank account (and an even worse way of doing money transfers.)
git is linear, if multiple users have a different main branch history you have a problem.
Pull requests in github is actually very similar conceptually to a consensus mechanism used in crypto currencies. Everyone has an identical copy of the main branch with an identical history of every commit in order, a PR is saying "I think this commit goes next" and, if you use code reviews, the PR approval is consensus.
Hah, sounds good. I still don't get your argument here, I would be curious to hear more.
My point is that git is a data store involving a genesis block (initial commit), blocks of changes/diff's, tracked in sequential order, and with a form of consensus (code reviews and merges to primary).
What is missing that makes it not a blockchain?
And my caveat here, I can't stand arguments for cryptocurrencies and have never purchased any. Blockchain as a concept is fine, and git is a blockchain as best I can tell.