Only if you plan on keeping them in an overcrowded monotonous environment in which there is nothing to do but pick on the next bored and frustrated bird... like they do in conventional meat turkey production facilities.
I doubt you'll find anyone here who debeaks their birds. Like Pampered Hen said, it's something they do in commercial poultry houses where they concentrate and confine the birds. It's a practice that prevents the birds from damaging each other when those conditions lead them to peck and cannibalize each other. In factory farms, they also remove snoods.
However, it's been my experience that birds raised in less-intensive ways (i.e.: in the backyard) aren't prone to that kind of behavior. If you asked them, by birds would probably say they like having their beaks: they use them for activities like eating bugs and pecking through the grass. Factory farms have no time for such silly, foolish, non-productive behavior.
I agree, unless you're running a hatchery, there is no reason to debeak any bird. However, some people feel that removing the snood (the dangly thing off the top of the beak) is beneficial to keep the toms from injuring each other. I don't see a reason for that either if you only have small backyard flock.