Because I enjoy riding, I go through a nice park and residential area of town on my way, and because I feel good when I get to work. I feel more connected with nature and the outdoors. And also, because, after 15 years of daily driving, I have come to hate the drive.
The cost savings and health benefits are not a consideration for me. I need to keep the car, so the cost savings are insignificant. I have not lost weight since commuting, my blood pressure has not gone down, and my cholesterol has not changed. My commute is 10 miles each way.