Killua is a special kind of troll called a "concern troll." They post bad/negative things for attention, but under the frame that they're asking the "tough questions" out of the concern and love for the thing they are posting negative things about.
Duo doesn't quite fall under that definition all the time. Just... a lot of the time.
(Filthy McNasty also doesn't fit under the category, since he is actually asking genuinely good questions out of love for the game and not just doing it for attention.)
Yea, I had a love/hate with Filthy, but I have to respect him, it took me some time to see that his heart is in the right place. He really does want to see the game go well, and really wants it to succeed.
And to be fair, I see the Killua/Duo difference, hence why my vote on Killua was PERMABAN and Duo was 1 month mute. Or 1 month ban, not sure, but not PERMABAN.