[9gunpi]

Git should have been written with pluggable hashes, right. Also, SHA1 could have been invented stronger against collisions in the first place.

In the retrospect many decisions which might have simplified current moment's problems are obvious, but in reality of those decisions in the past they never are. This feeling (it's called the retrospective predictability) is not a function of current problem or previous wrong decisions, but the random reality of events in complex systems, open source software implementing fresh ideas in a new way is being random and complex enough for this.