A kit lense is one bundled with the camera. As majority of buyers of DSLR are new and need a lense, kit lenses have a huge sale. I agree with the article that they are not "Cheap", just "less expensive" due to economies of scale.
As long as you know the limitation of your lense, you can get excellent results. I get good images with my 18-55, and as long as they are shot between F8 and F11, they compare in sharpness with my primes - 50mm F1.8 and 35mm F1.8. The primes have better micro contrast, but the kit lense the versatility. Another point that I agree with is the shorter minimum focusing distance. Some of the better close ups of flowers are with my 18-55 at 55mm.
Here are two images one with kit lense and one with 35mm prime