I see the questions similar to "What's the big deal? The earth being 4.8 billion years doesn't negate anything.... God is the creator when 4.8 Billion years ago so what?", etc... "God could've created instantaneouslhy or 20 billion years ago..."
You miss the point - it's not about what God COULD do or COULD have done - it's what He STATED He did. Do we believe Him who was there at the beginning or do we believe the views of fallable man who weren't there? That's the underlying question.