I was recently fit at Titleist and they were all over me to increase my angle of attack to a positive (rising) number. I did it with ball position and tee height, the spin numbers came way down as you say.
Well, it's a lot easier to get you to swing differently with the Big Dog than it is for them to design an even Longer Club. And it's much easier for everyone to understand "Hit Up" than understand "Swing from the Feet"
Ok, so it's the Brilliant Engineers at Titleist.
Conversation between Titleist Salesman and Engineer:
Salesman (Worried): Look buddy, you have the Engineering degree, so either give me a driver that makes the Ball go farther or this Pro will find another Club Maker to use.
Engineer (Worried): It's not the Club, tell him that he's not using it right. Tell him to hit up.
Salesman (puzzled): Do you think he'll buy that answer?