I know exactly what you mean, but your idea is impractical because of the issues as I have explained in my post. I'm sure if you look in this forum, you are not the first person to suggest this and there are probably many more reasons in those threads as to why the idea is not a good one in the first place.
Not that it is any consolation, but the thief will have to get past the passcode in order to use it, and if it is restored as new the phone will be useless as it will have activation lock enabled (assuming iOS 7 is installed).
You asked for opinions and you have to be ready to receive both pro and con opinions. In any case this thread is probably already close to violating the TOS which we all agreed to when we signed up. Don't be surprised if it gets deleted by the moderators. There are other forums on the web, where I'm sure discussions like this one are very lively.
If you still think your idea is good, then tell Apple and click on the link that Mac. Dee has provided. Apple does not read and does not participate in this forum.