Help Me Understand Why People Won't Help Themselves!!

I am really trying to understand, I am. But how can most people still stay unmotivated when they know that regular execise is good for their health... and I mean all over health? I hear many people say "I just don't have time..." well that to me means you don't have time to be healthy. I know if you have arthritis you hurt, and the thought of walking a couple miles, or working out at a gym can really hurt. But you can work out in the water without hurting your joints, and eventually you'll feel so much better from your increased range of motion that you'll soon be able to go to the gym. I even say forget the gym, let's face it--it is expensive and very often intimidating (not so much anymore...you'll see all shapes and sizes working at gyms now), a good alternative is exercise DVDs. Go to the website collagevideo.com--it's awesome. you can actually see a clip of each DVD and even talk to people who have done the workouts. I love it and have about 110 DVDs...that I actually use very often in my pj's right our of bed everyday. Trust me I do not work for them.
Regular exercise is really not a big committment. At least 30minutes/day for 4-5 days a week. If you're just starting break the 30 min. up to 6-5min or 3-10 minute sessions. Hey and don't forget --THE BEST GYM IN EVERY BUILDING IS THE STAIRWAY!!!
I promise you, exercise will improve your health, and make you actually feel and be well. And it won't affect your kidney and liver like medications do, AND THE BEST PART IS THAT EXERCISE IS FREE!
Exercise will improve your blood pressure, cholesterol, blood sugar, circulation, arthritis, balance, insomnia, weight management, depression, memory, sex life, energy & mood. And I'll repeat- EXERCISE IS FREE!
Also, I cannot tell you how many people will diabetes, arthritis & other chronic conditions have either totally gotten off their medications or cut their dosages in half because of regular exercise.
So, I ask you again--help me understand why people choose not to exercise when it it so good for them?????