It wasn't just about "nicking a mobile" though. In the case recently in the news, the guy who got 4 years, beat hell out of his victim. I saw the victim's mother being interviewed. She maintained that he'd said "take the mobile, just leave me alone" so in this particular case the phone wasn't the issue.
However future theft of mobiles should in my opinion be treated the same as having your bag or purse stolen.I know mobiles are expensive but the principle is exactly the same.