Does Canon really deserve this?

[jrista]

Even better, make a hybrid device...one that can operate mirrorless with an EVF if the user chooses, or switch back to mirrorslapping OVF mode on demand.

Such a device would indeed be BIGGER. But you might still not like it, since it would be fairly top-heavy with a "really big hump" to accomodate both: [an even more more complex] viewfinder prism AND the EVF [panel+electronics].

Not necessarily. If your mirror is reflective on both sides, you could design the camera to use the mirror in all photographs, with the mirror pivoting in the center. Then, place the sensor at the bottom, facing up. Place the LCD at the back of the camera, facing towards the lens. When taking a picture, or when in live view mode, flip it so that the mirror reflects light from the lens down into the sensor, and from the LCD panel up into the OVF.

That idea is even better! Either way, however you do it, there are ways of fitting an EVF into a camera with a standard mirror-slapping OVF. I'll take it however it's designed.