While I agree that Kramer could sustain a successful spinoff more than George could, the "Best Supporting" award is given for exactly that - Supporting. I think that besides looking at it in terms of which male is the second funniest, you have to think about the role of the supporting character: to support the main flow of the show, which includes the main character. As much as I like Kramer (yes, more than George), the fact is -in my opinion:-)- that George is a much more integral part of Jerry. Jerry is
"supported" by George in that to know Jerry and his situation and "who he is", you've got to look at George and Jerry's relationship to George. On the other hand, while kramer is a million laughs, he's more of a humorous annoyance to Jerry than a "support" for Jerry's character. While I definitely think the show would suffer without Kramer, I think it could continue, but without George, I'm skeptical, because not only would you lose George, but you'd lose part of Jerry. That's why George deserved to win.
You know something's wrong when I start psychoanalyzing a TV character.
-Mark