When did adapting to a changing situation become failure? Changing course when needed would imply accountability because one is taking ownership of their actions and outcomes from said actions.
Being proactive in adjusting plans means you're being accountable when your initial plan is no longer viable. It also means you're learning from the mistakes of the previous ideas.
A failure would be being completely inflexible regardless of how the situation changed.
Again, I'm talking in the general sense for anyone who is in any type of leadership position. If you want to apply it in whatever manner to Trump that's your choice. But that's not what I'm arguing here.
BTW. I'm still waiting for your solution of how we get from where we are now to where you'd like to see the US be.