I don't patch tubes because after several attempts, both on the side of the road and in my shop, most do not hold air and when they do I suspect that they will stop holding air in the middle of a ride.
I do not throw the tubes away though. I find other uses for them, such as bar wrap or sewing projects. On the other hand, I average about one flat for every 1000 miles or so don't have a lot of bad tubes.
I do carry patches though, and if ever I come upon someone with a flat, offer them a choice of my tube or the patch kit.