I'd have to disagree with ya there Nick only because in real life there are always going to be variations in your clubhead speed. Let's say for the sake of argument that I hit a SW 100 yards. Even if I take the club back to the belt position (50%) doesn't guarantee I'm going to swing through with the exact same clubhead speed every single time. This, of course, results in the variations we see in clubs in real life. On a real course, 160 yards is a relaxed 7-iron for me. Every so often I still manage to accidently blow it over 170 by swinging slightly too hard or too fast.
You have to think about it in terms of precision. If you have a bar telling you where 50% is your precision is going to be statistically higher than it should be. In other words, hitting 50 shots would result in 50 balls landing within inches of one another. However, when you remove the 50% bar now you blow a few shots long as well as leaving a few short. That's much more realistic I think.