There are plenty of us in the same boat. We don't need no stinkin excuse to do nothin. It just comes naturally. As for having had enough, I think it's a combination of the business changing over the years, and the fact that it's just that much harder to convince yourself you want to change with it.
In my case I spent years designing and improving packaging equipment in an effort to keep the company the leaders in it's field. When the latest round of management came along, they decided they wanted to change direction. They thought the company reputation would command premium prices regardless of the quality of the product. They didn't want to spend money to develop state of the art machinery. They wanted to get rid of the overhead and buy the same equipment that was being used by our competitors. They closed down the Machine Design department, got rid of the machine shops, and support personnel, and relied on outside vendors to build and maintain machinery.
This fall the last of the inhouse designed and built machinery will be phased out. We'll see how the company does. The replacement machinery runs at about 60% of the speed of the equipment it's replacing and requires almost double the number of people to run it.