Better to have a longtail where all eyes are on one family of implementations as opposed to several families . Critical failures are far less likely . I can certainly see the logic in that . However I do think it would be prudent to acknowledge the possibility of a critical failure in Core , even with all eyes on . Or if we ' re being meticulously cautious , the inevitability of a failure . Working under the fatalistic assumption that a critical defect will be found in Core sooner or later , what contingency can we prepare for such a scenario ? Having alternative implementations is the first that springs to mind , although that has drawbacks of its own . <| sep |> There are driving lessons , they ' re just not mandatory .