Based on what the OP has stated, it seems like this is either someone who is new to the craft of Photography or a joke thread. Nobody who is doing any kind of research would think that the 18-55 kit lens would work on a camera body that has Pro / Pricey / Technical / Built like a tank written all over it. You certainly wouldn't think that while holding the 18-55 lens.
I dont own a 1DX, but use one at job nearly every day. Being very familiar with most of the Canon FF non 1D series bodies I can honestly say that the 1DX is fantastic to use, but there are some things that bug me and work better on my 5D Classic.
For someone just buying one willy nilly, and not knowing how to navigate fluently around the technical menus, settings, button locations versus an APS-C body, or earlier 5D series body, it will seem very confusing and not easy.
The lack of a "Dial", huge battery, myriad focusing options, vast menus, heavy, and showy HAVE to play into someone's reason for purchase.
To be brutally honest, if I saw someone trying to mount a EF-S lens to a 1DX i'd think they are a dork.
BUT, to each his own, and maybe that "want" is just too tempting to say no to.