he's angry that his character whom he put together despite what the "suits" wanted was completely redone. And this hurt his feelings. And then beyond that, maybe he's upset that the original Apollo got a pretty major bit part/character through the entire series, and he didn't get anything.

And then beyond that, maybe he's upset that his cylons were big & shiney....where in the new series they were all fleshy and fun to hang out with (unless they tried to kill you). After all, if the cylons all looked like Caprica back in his day, he'd be rolling around with her on the floor of the ship.

~Jeordam