Filling in a plot hole

Okay, so I'm trying to fill in a big plot hole in Ocarina of Time.  The one that makes you think what was the point of the whole game, if everything could have been prevented by just not entering the Sacred Realm in the first place?

(Also, I'm doing this in script form.  My goal is to write a full-length movie adaptation trilogy for OoT.  I'm definitely interested in some die-hard fan about my approach to this scene, as I try to make it make sense.  So please be as critical as you want to be.)

Anyway, here's the scene segment.

ZELDA

All the tragedy that has befallen Hyrule was my doing. I was so young. I could not comprehend the consequences of trying to control the Sacred Realm. I dragged you into it too.

LINK

(slightly confused) Zelda, we were both chosen by Destiny. You didn’t drag me into anything.

ZELDA

(reacts as if she hadn’t thought of it that way, but her guilt overwhelms her again) But if only I hadn’t sent you to collect the Spiritual Stones then-

LINK

All the Gorons would have died of starvation, and Princess Ruto would have remained trapped as well!

ZELDA

(seemingly determined to blame herself for everything) Link, I… I watched for seven years as my people suffered and my kingdom deteriorated, knowing that I was the cause of it. I was so foolish. I should have… I should have…

LINK

Should have what? Ganondorf was already becoming more and more powerful. What else could we have done to try to stop him?

Zelda looks at Link, heartbroken for what her people have endured. Link realizes the weight of what she's been carrying.

ZELDA

(ashamed at herself) I don’t know…

She casts her gaze slightly downward. Link tilts his head in a “scooping under” motion to try to catch Zelda’s eyesight as he puts his hand on her shoulder.

LINK

(trying to tenderly add a bit of lightheartedness to the moment)  All this coming from the wielder of the Triforce of Wisdom?

Zelda raises her head to look at him again.

LINK

Honestly I’m surprised that the Princess of Destiny hasn’t figured this out yet.

Zelda continues to look at Link, confused and curious, waiting to hear his explanation.

LINK

Zelda, Destiny awakened both of us at the proper time to step forward into what we were called to do.  And the Sages.  Don’t you see?

Zelda still looks curious and confused.

LINK

None of us were prepared to win against Ganandorf, without having to first go through the process of becoming stronger ourselves.

ZELDA

(takes just a moment to absorb this idea)  You think we needed to fight against him for seven years…

LINK

To become powerful enough to defeat him today.