Are you thinking that it's like a Xmas tree where they shear them to make them fuller, or do you just think it would improve the esthetics? My opinion is that it would look butchered, but that's just me. In general, I've found that the best way to have "full-looking" bamboo is to plant a species that tends to that appearance and then give it the right anounts of water, light and fertilizer.

Pruni*g a Phyllostachys will make it much fuller. I have pru*ed my Vivax into a hedge and I really like how it looks. Atrovaginata that I've pru*ed really gets thick with foliage as well. Sometimes winter damage will kill part of a culm and part of the branches so I trim down to good wood. They always end up thick with leaves. I believe that the pruni*g encourages the culm to utilize dormant leaf buds earlier thus making it much fuller.