Not to mention that bitcoin being a protocol, it’s precisely the perfect use case for tdd. Define specs, implement tests, all nodes need to pass it.

Although I have no idea how such a spec could be drafted.

Also, as a nitpick, all software built today is the legacy software of tomorrow, so although I think bitcoin would benefit from this, I think that what was done so far was well done, in as much it was all fruit of free labor hahaha