Different people have different type of progress. Taking myself as an example. When I started out my photography journey, I was equipped with a 1000D and kit lens (18-55mm). Did have lots of fun. Then I got myself a 55-250mm to shoot faraway objects... however I came to know the 50mm f1.8 and got it because it is cheap and everyone was telling me that I needed it - I couldn't be more wrong. The lens although fast and having great image quality (I wouldn't say that it is far superior as compared to my kit lens though) was lying useless in my dry cabinet and finally, I sold it off at quite a significant loss.
So my point is... to some... the kit lens is going to be inadequate as skills advance further... to others, it is still a valuable asset to their photography needs. It all depend on the person, really.
And that is why, we have advise TS to get the kit lens first because it covered most of the most useful focal length for most people. He/ she can played with all these focal lengths and it is cheaper to get.
Finally, only by playing with all these, that he/she actually know what they wanted. For example, shootintg awhile with the 18-105mm, TS realise that he wanted to shoot macro, he can then jump into getting a macro lens. If he realise that 18mm is not wide enough for his landscape shots, so he can jump into getting a wider lens (say... Tokina 11-16mm). Or if he realise that he need faster lenses or only shoot at certain focal length, then TS can get the prime lenses of that focal length easily.
It is pretty irresponsible for any of us now (without knowing what TS is really geared for) to recommend specific lenses for him, he might end up buying all the stuff, spending all those money for something that will lie in his dry cabinet unused.
And it can be a sweeping statement to state that the kit lens is grossly inadequate because to many photographers (some of them are pretty good photographers) are actually still using their kit lens even after their skills have advanced beyond what they used to have when they started off.