There are times when the wheel at hand is an ill fit or perhaps there genuinely is a better way to do things Ex: Libressl. And so the wheel needs reinvention.

Reinvention of the wheel, reimplementation of a paradigm or some other repetition in a slightly different or totally different way isn't necessarily a bad thing as long as the underlying concepts are well understood and it is executed with competence. I still believe malicious tampering is unnecessary when carelessness - or tiredness - on the part of the developer will do just as well.