"Scott was right in many ways. However it's also worth stressing -- and I suspect this is the thing which most pro-Scott advocates are skirting over -- is that if we did everything like Scott said, the Earth would have been destroyed. Hope wasn't ready. She was ready eventually but that required time.
(That said, there's also the reading that Hope was always fine and could have dealt with it if she had too. I think that's a bit of a reach -- but we'll never know.)
Scott's position was always a fatalistic, providence-heavy one. The Avengers' resistance was all part of the universal plan. Scott taking the Phoenix for as long as he did allowed Hope to be ready. It all worked out.
That's the thing which makes Scott's mono-vision more questionable, for me. By believing it all worked out in the end does mean you remove the possibility that it could have worked out in a better way.
Though I suppose when you've killed your mentor and father figure, that's a question you may want to avoid for as long as possible." - Gillen for X-Position (Comic Book Resources)
I agree with Gillen. Hope didn't start training for the Phoenix until Scott forced the Avengers into action. Cyclops is "tragic hero" of AvX, the best X-Man who sacrificed his name for mutantkind.
One question, though: Cable was the one who told Scott to guard Hope at all costs. If Cable knew what the future held, why didn't he just tell Scott about K'un-L'un? Why did Cable hang his father out to dry?