Pop culture promotes the idea that computer security is like real life security systems, it makes for a better story.

In real life there is no way to keep people out, just slow them down. Safes are rated on how long it takes an expert with the proper tools to open them. But any safe can be opened.

In the computer world all the doors are 100% impenetrable, and if they are locked properly they can never be opened by anyone who wasn't given a key.

Only sometimes next to the door, behind the shrubs, there is a whole left there by the building crew.

Someone looks behind the shrub and says ah there is a huge hole there and anyone can walk through.

They are not creating the holes, they are just finding them.