"why something is written in a certain way" most likely doesn't even have an answer while a project is still in the rewrite-large-parts-frequently stage. Sure,

"why something is written in a certain way" most likely doesn't even have an answer while a project is still in the rewrite-large-parts-frequently stage. Sure, you could spend some time conjuring up an explanation, but that's quite possibly gonna end up useless when the code is ruthlessly rewritten anyway. That said, specific fixes or similar can definitely do with good messaging. Though I'd say such belongs in comments, not commit messages, where it won't get shadowed over time by unrelated changes.