Well I guess if motorcycles can have the light on high beam all the time, bicycles should be allowed that, too, in certain conditions. My commuting route has a nine mile stretch where part of it is a bicycle path and part of it is a multi use path. A few people cycle with high beams, and since the approaching angle is very small, I find it very inconsiderate. I have encountered one person who shuts off his bright light as he approaches me, so I'm grateful for that. I suppose you could also devise a visor to create a top-of-the-beam cutoff if you rode on bike paths, but if you rode only on roads, it shouldn't be necessary.