Wow. That's pretty lame.
I'm of the mindset that players have a public duty to sign some things. If they're worried about items ending up on ebay, they can always personalize the item (i.e., "to Billy", etc.)
I know Bill Russell never signed, either, but I was never a fan of that. Still, from what I understand, Russell was willing to shake hands, etc. From what you related about Ewing, it sounds like he was just being a jerk all around.