I'd always had one until my latest bike purchase, about 3 years ago now. The first year or so after I got that bike, I made do with leaning it against whatever was handy. But it was annoying, so I got one. Now all my bikes are kickstand enabled, and it's much more convenient.

The beefy one I use (so that it can hold up a loaded touring bike) adds a significant amount of weight, but it makes me much happier with my ride.