I couldn't imagine the horror, because I hold a bit of identity in my first name, & i think it would suck for everyone else to share it.
Also, how could you think for nine months & then go 'wow, you know what, John is the best name I can be buggered to think of'. "John!" 17 people in the room shout "Yeah". I just don't understand the logic. I'm sure in a few cases maybe John really is a cool name & you really love it. That's fair enough, but... everyone?