It's a running joke where I work just how hard it is to get fired. One of the few stories I know of someone who was fired involved an employee for whom my employer paid multiple times for courses of rehab. He was finally fired when after all that they found him at his desk so drunk they basically couldn't wake him at all.
On my first job, there were several employees whose jobs was to aimlessly wander around the office because they had a problem with their logins when they were hired and nobody bothered to fix it for them. Companies really don't give a shit.