There was a time when sitting down caused little rolls of fat to cascade down my stomach. These days I'm no longer mistaken for the Michelin Tire Man. I can torture my abs from every angle which keeps me from getting bored. I'm MUCH less likely to overeat. I want to be able to see my efforts.
Strong abs are fun to look at.
When the light hits me just right, I have three neat vertical lines, one down the middle and one on each side where my obliques meet my rectus abdominis. I don't have to lie down to zip my jeans. Strong abs and back keep my Rottweiler from using my spine as a Slinky when I walk her. I no longer need to be put in traction every time she sees a kitty. It's a good excuse to lie on the floor at the end of a killer workout.