I get what you're saying. But beyond a certain point, I can't agree with it. Slowing it down is a necessary requirement for building speed.
Everyone reading this can play crazy fast — right now — if they don't care what notes come out or how clean those notes are. But to play with speed
and competence, you have to develop the muscle memory that allows you to play smoothly without having to plan every stroke in advance. Because your conscious mind
can't perform all those calculations at high speeds. So you work that stuff out while playing slowly — when your mind has the luxury of performing those calculations and training your hands.
I watched the Troy Grady video you posted. The gist of his message is that if you want to play fast, then playing slowly isn't fast enough. Well, yeah.
At some point, you have to actually
try to play fast. Then, when you stumble, you slow it down and try over.
In that video, Andy Wood says pretty much the same thing. When he's working on something new, he charges in fast. When that doesn't work out, he "takes it apart." He breaks it into chunks and slows it down. Then, when it "feels smooth," he moves on. I wouldn't put too much mystique into that "feels smooth" thing. Remember that Andy has thousands of hours of dedicated practice, multiplied by a whopping dose of natural talent, to inform that "feel." He already knows how to play fast when he's trying to work up a new fast riff.
And I totally don't get his comment, "It's like learning to ride a bicycle. Sometimes you have to floor it." No one learns to ride a bike by flooring it. The first time you floor it on a bike, you've already mastered the art of staying vertical at reasonable speeds.
So slow it down, and learn the lick.
Then give it some gas.