I'd actually flip that. I think the extra DR is the cake and the tilt screen is merely an added bonus. I've never taken a "lesser" picture because I didn't have a tilt screen. WIFI is completely useless to me (I'm sure it serves other ppl very well, just doesn't fit my own workflow) so I don't care either way. And I agree that competition is always good. It forces everyone to stay serious and we are the ones who benefit from this.
Yeah, different strokes for different folks. Fortunately, for most scenarios that may be DR limited, I'm able to adequately control DR through other means. On the flip side, a tilt screen would come very handy for me when a shot requires extremely high or extremely low angles. As for WIFI, although I wouldn't use it all the time, it would be very handy for gigs that require immediately uploading images onto the web. Shuffling memory cards to a tablet or laptop is a pain.
Either way, the D750 at least includes these features and lets the end user determine how relevant they are to each user's needs. No such luck with the 5D3, but then again it is approaching three years old at this point.