This thread makes no sense.
This thread makes perfect sense, socially. Someone sees something that doesn't makes sense and is asking why. The reason cameras and not houses or cars is separation. People who buy a $1M car have already spent much more on separating themselves from those who would not. What's odd here is that the Rebel and the 1D are made by the same company and the owners of both inhabit the same message board, exposing each group to the other. People on Honda boards don't inadvertently see posts from people on Ferrari boards.
The question of how has been answered, because they can. I would add one economic lesson. My father was one of 14 children. It was a dairy farm and children were economic assets. Their presence added to the strength of the business and he more less paid for himself growing up. Forward one generation and he had 3 children. My sisters and I did not pay for ourselves. While I helped with assembly from time to time, there was no daily activity we could do to make 11 more siblings easily affordable.
So to with cameras. One that contributes to it's own expense and that of other gear and eventually to its own replacement, does not require personal income to exist. I bought a 20D with personal income, used it to make money and bought a 7D. Used it to make money and bought a 6D. My current setup is the most economic value I can produce with my current work, so this is the most camera I expect to buy (more camera does not make more valuable photos for my style of picture).
Make your next purchase outside of personal income and get away from its constraints.
The only people I'm really insanely jealous about are the ones who have an old Rebel EOS body and a nifty fifty and consistently take photos that blow me away.
Amen