And also Robin derived as a diminutive of Robert, not from the bird, so certainly historically boys called Robin weren't named after birds, they were usually actually called Robert. The bird was named after the male name, not the other way around.
Not that you need to know the history of a name, but it helps to explain why people react differently to something that has been established and around in popular culture since they can remember (Robin Hood, Robin Goodfellow etc) and something that has only recently been used.