Yes, to get those cleaner images, I'd get more low-ISO DR for free. But there's really only one time I've wanted more base-ISO DR and in that particular case, I needed about 20 more stops, not a measly 2 stops more.
I generally get where you are coming from.
BUT that's not how folks in the market for new DSLRs view the situation. Everyone turns to DXOMark these days (including DPReview). Whether DXOMark numbers make sense or not is another matter. It does not change how people perceive Canon sensors when they look at DXOMark camera ranking; not one Canon camera is in the top ten right now. That has a very serious impact on buyers' perception, hence the loss of Canon market shares to Nikon.