Please NEVER leave your doors unlocked. Not even if you live in Timbucktoo with three people living in a town 30 miles from you. Any evil stranger in your area can take that chance turn into your driveway. Even locked won't stop most of them, but it will slow them down.
It's a scary world now, most have forgotten any respect, morals or ethics they were taught (or maybe they never were taught). We know from schools today, there is no respect for authority and on the street, none for law enforcement.
I'm so sorry for your loss when your home was burglarized but am so thankful no people were hurt. Our doors are locked, all the time when we are home and gone and no one wants to break in, believe me. I don't even answer my front door as I can go to a front window to see who is there before letting anyone in. My husband was in law enforcement for 25 years.