As the saying goes, quality lenses are a lot more important than good bodies when it comes to investing in camera gear. They last longer, retain their value more, and have more utility overall than, say, buying the latest DSLR that will become obsolete in 3 to 5 years. But if you are into photography for the first time, you’ll likely buy an entry level camera that comes bundled with an inferior, even crappy, kit lens. Or is it?
I wouldn’t go so far as to say your kit lens is an “excellent” lens (even the linked article lists many of its flaws) but I tell all beginners to not think about buying new lenses until they learn to shoot better and learn how to use their camera. It’s like a beginning driver getting into a Ferrari – all that extra power does you no good if you don’t have the experience to use it.