It isn't because the feds want to be the hero. I'm a wildlife rehabilitator. I can't tell you how many times I've seen people try to 'do the right thing' and improperly care for an animal resulting in improper growth or something that makes them unreleasable into the wild. The reason the Migratory Bird Act exists is to prevent whole populations being decimated. It's in place so the balance of the ecosystem isn't thrown wildly out of wack. You may think it's just one bird, but it may go on to spawn many others or bring down invasive species etc. I know it isn't a malicious act in everyone's eyes but it's really better to let the professionals do it and let the animal live as natural a life as it can.