The alternative to this would be Brock on every Monday Night RAW and every PPV, running over guys like Sheamus or Big Show or Ambrose or whatever top babyface you want to throw at him, repeating the exact same angle he just had with John Cena. And why should he? It serves those guys no purpose to lose to Lesnar since we know they wouldn't stand a chance, and doesn't make Lesnar look any tougher by defeating them.
To put it in even simpler, somewhat ironic terms, compare Brock Lesnar to the Undertaker. We don't need Taker to wrestle every Smackdown! show and PPV leading up to his match at Wrestlemania. Because if he did, his Wrestlemania match wouldn't be nearly as special. Undertaker's streak was a spectacle, the same way that Brock Lesnar's WWE World Championship reign is a spectacle. I'm all for this.