My best somewhat-educated guess is simply Canon is trying a different approach with their compact system camera (CSC) line. While it may make sense for a large and bulky DSLR to come with a large wide zoom lens, a CSC is meant to be generally smaller and more accessible. The Sony NEX and Samsung NX CSC's look a little off-balance with a zoom attached, and they certainly aren't pocketable/pocketbook-able with a lens attached that is as long as the camera body is wide. It also doesn't look like Panasonic has had much luck with their collapsable power zoom for Micro 4/3, and I would refer to the performance of the Olympus collapsable kit zoom as being 'just okay'.
Another thought is the 'fast prime' 22mm f2.0 pancake lens might also be better for showcasing the abilities of an 18MP APS-C sensor than an 18-55mm f3.5-5.6 wide zoom lens.
Yet another thought: It could also just be that the 22mm lens is cheaper to produce.
Kit lenses are notoriously poor quality, in both build and performance. 22mm at f2 is an excellent all-purpose lens which allows for a compact form factor and ease of use in most situations. Add the 50mm prime for $100 and you're set! (The 18-55mm kit lens is available separately for around $150 if you are just lazy and want one all-around lens with mediocre image quality.)