Jeff,
I do recall Tom Gray telling us he's driven that little green there, at Franklin Hills' 14th. Man... that's an amazing shot. How big's that green, atop that volcano-like knob? About 1,200 sq. ft., I think.
It's a type of shot that's difficult to comprehend. But, it's apparently possible.
The difference between Franklin Hill's 14th and this hole at Valhalla is the latter presents "death" around the green (water). To my way of thinking, this factor (should) discourage more players from trying to drive the ball onto the putting surface. Conversely, missing the green at a hole like FH's 14th simply leaves a challenging pitch to a tiny green, played from grass. There's no serious penalty.
I prefer a short par-4 that really encourages players to "go for it", and where recovery play is complicated by contour and slope, and perhaps a couple bunkers. Water doesn't help this cause.