Why So Against Popup Flash??

Personally, I'd like to see popup flash on the next generation 5D. Why are so many people against this typical camera feature? For weddings and other pro gigs, I use my 580EXII with my 40D. When I'm just out and about, I use the onboard flash. Having a popup flash doesn't somehow prevent you from using an external flash. It's a usefull (and occasionally necessary) feature to have in a camera.

Unless the whole idea of the 5D line is to be solely a studio/portrait camera. The 1Ds is a studio/landscape camera, so no popup flash is usefull. The 1D is more a sports camera, so it's understandable not to have flash on that one either. But what exactly is the 5D? It's definitely not sports at 3fps. So then, is it a portrait camera? Or a landscape camera? I'm understanding it was initially released in Japan as a pro-sumer grade "wedding photojournalism" camera. Then that would make it fall under the 1Ds line, not the 1D line. Then, as an entry-level "pro" grade FF portrait camera, I think it should have built in flash.

I would find it very usefull. Just my opinion.

--
Insert pretentious obligatory quote here...