This can be true while it still keeping most criminals out. It's going to depend on the location and context. I'd say an analogy for this is engineer thinking versus economist thinking. My observation is that criminals prefer the latter. Rather than doubling down on engineering, they try to move to a more lucrative venture. Getting better at burgling houses doesn't change the upside as much as other crime.

In my suburban area, the biggest problem is unlocked doors on houses and cars. Despite this problem existing for many years, doors are still regularly left open. The criminals don't attempt to exploit the same neighborhood repeatedly. They pass through in waves and then go elsewhere before returning when everyone has let their guard down. When they attempt forced entry, or anything more than casual theft, they get a lot of attention and caught.

They could improve their takings by developing some lock picking skill, but it's also higher risk since they have to spend some more time on each target which increases the risk that an observer will actually notice them. I could easily imagine a dog walker ignoring someone entering a home through an unlocked door, or making it look like they are checking a door is locked when entry fails.