I think you guys are missing the context of it a bit. Marshall probably said "just go ahead and play some fast licks". In a situation like that you're not expected to break out into the most melodic piece of music ever, you're supposed to make 13 year old kids want to buy an amp that will make them think they can shred like Zakk Wylde.
I do think his playing is boring, but I wouldn't cite that video as an example as it's not supposed to be interesting in that video.