Lets go back a couple of years.
In the film SLR days, you could get an SLR and as a KIT lens you had a 50mm f2 Lens. They created amazing images. They were cheap and produced wonderful quality for the price given. Just like today we have the 50mm f1.8.
With the introduction of Digital SLR cameras, the companies had to appeal to the beginners, which is most companies bread and butter (Except Leica).
The 18-55 is
- Remember it is an EF-S lens. So only to be coupled with crop bodies.
- Cheap (Because it is mass produced to go with the Body), they can pack this lens and a Body within $500 !!
- a Zoom Lens (People want to zoom, few beginners have idea about prime and zooms), this appeals to a lot of users, people such as my DAD and my cousin and my teachers.
Given used properly 18-55mm can produce nice images. If the person is interested, he can always get a better lens. You will notice that higher end bodies doesn't usually come with a kit (if it does, its usually an expensive kit, such 5D mark II has the 24-105 F4L), because people who buy a 5D mark III or a Nikon D800, usually has a pretty good lens or can afford a good lens, giving them a kit option is nearly impossible.
If you are buying T4i, get it and get the 50mm f1.8 . Check out my gallery
gearspec.deviantart.com and even 50mm f.18 Flickr galleries, you will not be disappointed. Anyone good at photography has a 50mm in their bag (Although on a T4i it will work like a 80mm), still a thousand times better than 18-55 and you get to use your feet to zoom.