Well, I disagree. Modern optical viewfinders are dim (as you rightly observe) and not nearly as flexible as their digital counterparts. The idea that you're seeing what the lens is seeing is patently false, and even if it wasn't - I'd rather see what the sensor is seeing.
I'm not sure if you've used many of the pentamirror type DSLR finders that are on cheaper bodies, those are truly dire. Yes, on some digital finders you can see the dots, but I tend not to be looking at the image, not the dots and the lag really should be small to nonexistent on anything recent and decent. Peering through my D600's finder I see vignetting, low contrast, probably distortion from the optical system and it's impossible to judge focus with a fast lens.
Maybe we just shoot different things. I don't do a lot of high-speed panning for example. I could imagine an optical viewfinder might be better for that. Every time I manual focus a lens on a DSLR and I want to be spot-on I feel like I'm trapped in the dark ages. Where's my zoom? Where's my peaking? The one negative I have found is that, at least on the Nikon V1 I use as my carry-around, the refresh rate seems to be affected by temperatures close to zero, or below.
Give me a digital camera with the viewfinder of the OM-1 and perhaps we'd be in business.
Another reason why I love my x100, both options! OVF and EVF