I guess it just feels like it would, or just does not seem as powerful (feeling) as swinging it out away and up. That's what I attempt to do when driving the ball. To be fair, I really have not tried it enough with fairway woods and driver. With my irons I have been feeling my arms get moving down first, with a pull length wise for initial start down immediately followed by a tumbling the club head left and a bent left wrist right after impact. I try to blend all of that into one continuous motion when playing, but experiment with each separate component when practicing. It has worked nicely with wedges through six or five but I revert back to a more inside out motion with longer clubs because it is more comfortable.
He played college golf at Point Loma Nazarene College in San Diego and was the NAIA champion I think for 2 years. I think he's playing the mini tours now. I don't know him, I heard of him from, I think, the regional fox sports channel here in California a few years ago doing a story on the NAIA golf championships and saw his video in the "lay off" thread. That last name in hard to forget.