The phrase predates the 3-pt revolution, as far as I know. But I agree with that element of the game's effect on blowouts. Basketball at every level is defined by the hotter team winning with great regularity. Same for most team sports, with "makes and misses" replaced by "complete and incomplete passes" or whatever. It's a completely frivolous phrase that gets repeated like it's some ancient wisdom.
Houston was the aggressor, and on their home court. Plowing into defenders, pushing off, throwing their bodies across the defenders' lower extremities, travelling on their step backs. You know, Harden/Paul stuff. Also, what others said about moving the ball around quickly and getting everyone involved, no hesitation on their shots, and the role players came through. And GS seemed to be pressing, and missing. Rushing isn't the same as being aggressive. What's that saying about play fast, but don't hurry, or something? GS better sweep at home or Houston might take this.
You are right. Houston was hot hot hot. Last night they fell back to Earth and lost by what was it? 40? I doubt Stotts would have lost by 40.