To look right?
But fashions change.
When I collected my Thorn I wanted the steerer tube left long. Yeh,I had some cut. But I have an arthritic condition in my neck and thoracic spine which inhibits my former lower riding position. Am also older than I was 10/20 years ago. And who when 50/60+ rides as they did when 25,on the drops. Those days are long gone for me. Now,I actually like to see some stem protruding from my bars;it gives me the option and reassurance that I can notch up another bit,make cycling comfort better,allow me to look over the bush. I even like the look. Read somewhere where the look of aheadset was seen as ungainly,now,you look-see at a quill stem and that looks spindly++
Not convinced it could prevent injury given an accident. Guess you could do better wearing a breast plate protector or some knee pads. Or wotsabout an anti-collar bone breakage contraption?