Obnoxious or not, I think the point of contention is whether a theme can considered a derivative work or not. I think you can easily find lawyers who would have no trouble arguing either side of the case.
Did you watch the whole interview? His views has nothing to do with laws, nothing to do with grey areas within the license (from my understanding GPL is very explicit about this); he basically said "I don't wanna do this because, I don't wanna do this."
How can you rationalize with that?
EDIT: Not many licenses have been challenged in court, including the GPL. Do you have any cases to cite in favor of GPL?
I don't think that Thesis is distributed with a copy of Wordpress. I definitely think it's a sketchier argument to make with a theme. Settlement of a case doesn't always mean that the defendant is going to lose either. It can also mean that the cost and distraction of a protracted suit makes it easier to swallow the cost of the settlement.
Not to say that his argument couldn't fly, but I'm not sure I would give it that much credence either.
While Chris may not have stuck on point about the gray areas within the license (it is FAR from explicit), that doesn't mean they don't still apply. And last I checked, we're still innocent until proven guilty in regards to the kinds of accusations Matt is making.
Matt is the one with the burden of proof here, not Chris and Matt most certainly hasn't achieved the requisite level of proof IMO.