I can totally understand your point, but I think that if you look at the weight of history, you can probably see it is inevitable.
Look at all of the developments in camera features over the history of the technology-
on-board flash
Auto Exposure/Metering
Auto Focus
Film-> Digital
Just to mention a few
I'm sure at their respective times, each of these features was both highly anticipated and/or reviled due to the fact that the "took away" from the "old ways" (I'm too young in age and taking pictures to remember
If you think about your comment for pro/semi-pro vs. P&S, that's like saying that because I only do projects around my house occasionally, I should go to Home Depot and buy a Ryobi miter saw instead of a contractor grade DeWalt or Rigid. I have the skill/budget/inclination, why not buy up? I certainly wouldn't hold a laser cutting guide against the DeWalt because less experienced or casual woodworkers use it on a Ryobi (I love it on my Rigid).
I think that we are looking at a path of convergence, not divergence in the functions our equipment. Didn't one of the cellphone makers release an 8MP cellphone? I, for one, foresee that we will have "imaging devices", not still cameras or video cameras. Since there is no consumer or semi-pro video camera with a sensor the size of the Rebel/xxD/xD cameras, I would consider it quite a coup to get that kind of sensor to shoot video AND great stills for not much more than the price of a high-end consumer video camera (not including lenses, obviously).
I'm also really glad to see that this thread has remained a very friendly discussion, and not deteriorated into senseless arguing
Adam