The 1125 was essential to make inroads into racing. Really, racing is where sportbikes gain their legitimacy. As much as we all LOVE the XB, the greater sportbike population doesn't see it as a legitimate sportbike. The 1125r changed that and is/was the key for allowing Buell to grow as a company.
If HD didn't devour the Revolution engine and "cruiserize" it, Buell might have gained that legitimacy even earlier in the AMA circuit. Buell might even be competing in World SBK at this point if that had happened.
Developing the XB line allowed the 1125 to have a ready made, race worthy chassis. This proves the XB's worth. The XL engine just isn't race worthy in the SBK class (or Sportbike class for that matter).
What would be great, downright awesome, is if a BIG player stepped up and consumed Buell. BMW, Honda, Yamaha, Suzuki are all parts of a MUCH bigger operation. If someone like Ford (who declined the bailout, btw) took Erik in and let him build sportbikes under their brand name, imagine what kind of push Erik would get to achieve his vision? It's just a thought, something to ponder.