Maybe the droids would shoot at Boba if he ran out there. I mean, don't the droid fighters shoot at Slave 1 on its approach to Geonosis? I've always wondered why they did that. Maybe they figured Jango had outlived his usefulness and were trying to tie up some loose ends. So maybe Boba wouldn't be very safe if he went galabanting out around in a huge battlefield with tens of thousands of killer death robots and killer death clone people.