It does cross-reference them. But read the rest of my bullet points. It isn't just about cross-referencing. It's about cross-referencing in a way that encourages a vital community that resonates with SE's gamified nature by keeping the site fun for all players.

Closing with a link to the original is cross-referencing in a way that does just the opposite: It decreases the vitality of the community by taking away opportunities for newcomers to take part in the gamification feature.

Let's frame the issue another way: What's Stack Overflow really for? Is it for people to ask questions and get answers? Or is it just a gamified Wikipedia?