I can see canon-Clark having the conversation up to the "No, but..." part, and coming up with a convincing and workable reason to bakc out of this.
Hmmmm. So, why didn't alt-Clark?
I am guessing because he has not had the influence of M&J in his life, and he heavily lacks the confidence that having kind and loving parents gave canon Clark.
He was at school. She was at school. They both had busy schedules. It wasn't until he had been back at school a while that he realized how good he had it with Rachel.
That last part makes the most sense. Still, since Clark can get to where Rachel is in virtually no time at any point, I still think his busy is not a good excuse. Proably the real reason is he is afraid that he would find out that it did not mean to Rachel what it meant to him.
