They broke in because they wanted to. There is a misconception out there that security alarms will stop people in their tracks from breaking in to your house/business. That there is some invisible force field by way of a warning label on your door or window that will make the bad people go away.
To be quite frank, doors, locks, alarm systems, video surveillance systems are great deterrents and will always keep the honest people continuing to be honest. These devices are deterrents, but their primary function is to detect the intruder, provide a message or warning that this event is happening and reduce your losses.
To limit your attractiveness is to increase your mindfulness of your security and risk management practices. If don’t want to be a target of crime, you don’t have to be. It’s not to say it won’t happen but your losses will be reduced, you will have a quick turn around and continue business, you will back on track to profitability.