Thanks for sharing the link.
I found some of the answers interesting:
"And perhaps flawed characters are more interesting because they are forced to make a choice . . . a conventionally good character will always do the moral, right thing. Boring. Sharpe often does the right thing, but usually for the wrong reasons, and that's much more interesting!"
I think they are being way to shallow about "conventional good" characters vs flawed characters. All characters should be flawed otherwise they are not interesting nor even remotely real. We are all flawed. We all have things we struggle with, and we'll all do slightly bad things in certain situations. That's only normal.
If characters are not forced to make tough choices, then the STORY is boring, and that's the author's fault. A character does not have to be "gray" (in this context, I take that to mean has an evil streak to them that is apparent and accepted by the character), to force them to make bad choices, or choices that cause harm. A character who tries to be good, moral, and wise will still make stupid mistakes that cause harm (if they don't then again, that's a story problem).
So, I don't exactly understand what they mean about a "conventional good character". They seem to be referencing Tolkien here, but I don't see that either. Sam was possibly the "goodest" character in the story, yet he was flawed. He couldn't see any good in Gollum even though Frodo could. Sam fought his demons along the way. It was his love of his friend that gave him strength to do what was necessary in the end. Although Tolkien may be guilty of making his good a little too good, and his evil a little too evil, one has to take into account the era that he wrote in and the type of epic story he was writing. Plus, I think all his characters were flawed enough to make them interesting.
A non-flawed character is a boring one, for the most part. But more importantly, the story is probably lacking if any character is not forced to make difficult choices that probably go against their normal nature.
I really found the last few comments funny -- about why did GRR kill off Eddard?? Well, gee, let's see, he was a flawed interesting character that believed in honor (probably too much) -- one of the few in GRRM's books that one could characterize as "good". And Bernard laments him getting killed off after saying that 'good' characters are boring?
Anyway, I realize that both men have a lot more to say on these topics than what they have in that interview. I've never read Bernard, but have read GRRM. GRRM knows what they are doing. I just found it a bit odd for them to word things the way they did.