Earlier quoted context omitted.
Having used both, I find github's tools (mostly) better. And bitbucket isn't 100% reliable either.
Self-hosted is.
I can learn from my mistakes and improve progressively.
If I rely on another instead, I cannot, and I cannot (necessarily and confidently) see to it that they learn from their mistakes and improve.
By relying on another (at least an unreliable \ uncommunicative \ uncooperative one), I cannot improve my chances of them not making those same mistakes again, taking me down with them.