Well, for the past 40 years Intel managed to deliver node shrinks mostly on time. Management got used to that and thought that 10nm troubles were temporary, not something that required new design like rumored 10/12nm hybrid replacing original 10nm plans.

Intel might not have been able to make alternative decisions anyways. Cost might have made them choose between 10nm sooner or more 14nm now, and not betting on 10nm could easily have cost them more. Hard to say without insider info.