Everyone should be educated on ladder safety, and most of us do know how to use ladders safely... It's when we make the decision to simplify or quicken our process by using a ladder incorrectly that puts us in danger. Even if everyone took a safety course, and were professionally trained and certified in ladder safety there would still be incident. It could be from accidental human error, or negligence. You can't prevent all accidents, but you can try to eliminate most of them.
Two things I add to every ladder are stabilizers and levelers. Combined with proper ladder safety and handling, make your workday much safer. With the minimal cost to add these tools to your ladder, it's a no brainer for most of us in the industry.